Refrigeration apparatus and method

ABSTRACT

A heat exchange system includes a first reservoir having a first and second point and a first thermal material contained in the first reservoir. A first thermal contact is thermally coupled with the second point. Application of a force to the first thermal material can result in a temperature difference between the first and second points.

CLAIM OF PRIORITY

The present patent application is a non-provisional of, and claims thebenefit of priority of US Provisional Patent Application Nos. 62/584,125filed on Nov. 10, 2017 (Attorney Docket No. 5161.001PRV); 62/708,959filed on Jan. 2, 2018 (Attorney Docket No. 5161.001PV2); and 62/766,143filed on Oct. 3, 2018 (Attorney Docket No. 5161.001PV3); each of whichis hereby incorporated by reference herein in its entirety.

BACKGROUND

Heat typically flows from a hot thermal reservoir to a cold thermalreservoir when these two thermal reservoirs are in thermal contact witheach other. This heat can be transferred via conduction, for instance.

A conventional heat pump requires mechanical work to be done in order totransfer heat from a cold reservoir to a hot reservoir. For example, aconventional refrigerator consumes electricity in order to remove heatfrom the cold interior and deliver heat to the warm exterior, such asthe room in which the refrigerator is located.

A conventional heat engine performs mechanical work by absorbing heatfrom a hot reservoir and transferring heat to a cold reservoir. Forexample, in a marine steam engine, the working material absorbs heatfrom a hot reservoir in the boiler, and subsequently performs mechanicalwork, e.g. on a steam turbine, whereupon the steam transfers heat to acold reservoir, e.g. the ocean, in the condenser.

It would be desirable to provide improved thermal systems.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 is a cross-sectional view of one exemplary embodiment of a heattransfer apparatus.

FIG. 2 is a plot of material properties for the exemplary embodiment ofFIG. 1 in equilibrium.

FIG. 3 is a plot of material properties for another example of theembodiment of FIG. 1 in equilibrium.

FIG. 4 is a cross-sectional view of another exemplary embodiment of aheat transfer apparatus.

FIG. 5 depicts a plot of pressure versus specific volume, whichindicates the variation of parameters at different locations within anexemplary embodiment shown in FIGS. 6A-6B and at different points intime during one example thermodynamic cycle during operation.

FIG. 6A shows a plot of normalized material properties as a function ofposition along a length of the apparatus at a particular instant in timeand FIG. 6B portrays a cross-sectional view of one exemplary apparatus.

In FIGS. 7A-7H a cross-sectional view of the example apparatus of FIGS.6A-6B is shown in different configurations in accordance with differentpoints in time during one example method of operation shown in FIG. 5.

FIG. 8 is a plot of material properties for one example embodimentduring one example method of operation of any embodiment, including FIG.8 or 11.

FIG. 9 is a plot of material properties for one example embodimentduring one example method of operation of any embodiment, includingFIGS. 9 and 13.

FIG. 10 is a plot of material properties for one example embodimentduring one example method of operation of any embodiment, includingFIGS. 10 and 12.

FIG. 11 is a schematic representation of several embodiments of theinvention.

FIG. 12 is a schematic representation of several embodiments of theinvention.

FIG. 13 is a schematic representation of several embodiments of theinvention.

FIG. 14 is a cross-sectional view of one exemplary embodiment of therefrigeration apparatus.

FIG. 15 is a cross-sectional view of several components of anotherexemplary embodiment of the refrigeration apparatus.

FIG. 16 is a cross-sectional view of one exemplary embodiment of a heattransfer apparatus.

FIG. 17 is a cross-sectional view of one exemplary embodiment of a heattransfer apparatus.

FIG. 18 is a cross-sectional view of one exemplary embodiment of a heattransfer apparatus.

FIG. 19 is a cross-sectional view of one exemplary embodiment of a heattransfer apparatus.

FIG. 20 is a cross-sectional view of one exemplary embodiment of anartificial heat source or artificial heat sink comprising a heattransfer apparatus.

DETAILED DESCRIPTION

Heat typically flows from a hot thermal reservoir to a cold thermalreservoir when these two thermal reservoirs are in thermal contact witheach other. This heat can be transferred via conduction, for instance.

A conventional heat pump requires mechanical work to be done in order totransfer heat from a cold reservoir to a hot reservoir. For example, aconventional refrigerator consumes electricity in order to remove heatfrom the cold interior and deliver heat to the warm exterior, such asthe room in which the refrigerator is located.

A conventional heat engine performs mechanical work by absorbing heatfrom a hot reservoir and transferring heat to a cold reservoir. Forexample, in a marine steam engine, the working material absorbs heatfrom a hot reservoir in the boiler, and subsequently performs mechanicalwork, e.g. on a steam turbine, whereupon the steam transfers heat to acold reservoir, e.g. the ocean, in the condenser.

According to the literature, the sum of the entropies of thethermodynamic systems interacting with each other in a thermodynamicprocess increases or remains constant.

In some situations it would be desirable to provide thermal systemswhere heat flows from colder to hotter regions or where heat flowsfaster than existing systems. It would be desirable to provide improvedthermal systems. At least some of these challenges are addressed by theexemplary embodiments disclosed herein.

FIG. 1 is a cross-sectional view of one exemplary embodiment of a heattransfer apparatus. Various heat flows are described but this is notintended to be limiting. One of skill in the art will appreciate thatthe embodiment may include heat flow between any two points and mayinclude heat flow between any other two points. In this particulardepiction, the apparatus is configured to exchange heat between twopoints in a reservoir or between a first reservoir 2 and a secondreservoir 7. The first reservoir 2 contains material A 1, while thesecond reservoir 7 contains material B 8. Also shown is a thirdreservoir 18, containing material C 16, and a fourth reservoir 19,containing material D 17.

FIG. 1 shows a heat exchanging apparatus 3, which is configured tofacilitate heat flow between one set of two points as described below,or between any or all of the two points described below. Heat flow maybe between the first reservoir 2 and the third reservoir 18, a heatexchanging apparatus 20, which is configured to establish a thermalcontact and facilitate heat flow between the third reservoir 18 and thefourth reservoir 19, and a heat exchanging apparatus 6, which isconfigured to establish a thermal contact and facilitate heat flowbetween the fourth reservoir 19 and the second reservoir 7.

Heat exchanging apparatus 3 comprises an element 13 which is in thermalcontact with material A 1 in the first reservoir 2, as well as anelement 4 which is in thermal contact with material C 16 in the thirdreservoir 18. Heat exchanging apparatus 6 comprises an element 5 whichis in thermal contact with material D 17 in the fourth reservoir 19, aswell as an element 14 which is in thermal contact with material B 8 inthe second reservoir 7. Heat exchanging apparatus 20 comprises anelement 23 which is in thermal contact with material C 16 in the thirdreservoir 18, as well as an element 24 which is in thermal contact withmaterial D 17 in the fourth reservoir 19. Each element represents theportion of the associated heat exchanging apparatus which is in directthermal contact with the material in the associated reservoir. In FIG.1, one can consider an element to be the portion of a heat exchangingapparatus which is not enveloped by insulating apparatus 15.

The three heat exchanging apparatuses 3, 6, and 20 are configuredsubstantially identically. In other embodiments, this need not be thecase. In the embodiment shown in FIG. 1, the heat exchanging elements 4,5, 13, 14, 23, and 24 are configured to exchange heat with therespective materials via conduction and via electromagnetic waves. Forexample, the aforementioned heat exchanging elements may be solid, andmay be made of a material such as copper. In other embodiments, othermethods of establishing the thermal contact between the heat exchangingelements and the respective materials in the associated reservoirs, suchas element 23 and material C 16 in the third reservoir 18, may beemployed.

The thermal contact between the elements of a particular heat exchangingapparatus, such as element 23 and element 24 of heat exchangingapparatus 20, can be arranged in several ways. In FIG. 1, heat flowbetween related elements is enabled by thermal conduction. In otherwords, heat absorbed by element 23 is able to flow to element 24 via thephysical contact between said elements. In FIG. 1, this physical contactis provided by a third element of a heat exchanging apparatus, where thethird element extends through, and is enveloped by, insulating apparatus15. In FIG. 1, all three elements of a heat exchanging apparatus aremade of the same material. In this case, a heat exchanging apparatus maybe constructed of a single piece of material.

In other embodiments, the thermal contact between the elements of aparticular heat exchanging apparatus can be facilitated via forcedconvection. For example, a heat exchanging element such as element 23may comprise a fluid which can be configured to flow through a cavitywithin the heat exchanging element. The heat exchanging element may takethe shape similar to the shapes shown in FIG. 1, with the exception thatthe elements do not have a solid cross-section but rather a tubularcross-section enclosing the aforementioned fluid. A separate pump can beconfigured to move the fluid around a closed path, such as the pathformed by the elements of a heat exchanging apparatuses shown in FIG. 1.Said fluid can be employed to absorb heat as it travels through aparticular heat exchanging element such as element 23. The fluid can besubsequently or simultaneously pumped to the second heat exchangingelement of the heat exchanging apparatus, such as element 24 of heatexchanging apparatus 20. While traveling through the second heatexchanging element the fluid can transfer heat via conduction to thesecond heat exchanging element and subsequently to the adjacentmaterial, such as material D 17 in the fourth reservoir 19. Theaforementioned fluid can be water or a gas such as air, or any othersuitable fluid. Those skilled in the art will be able to identify asuitable fluid for a given application, such as a fluid with a highcoefficient of thermal conductivity and a low viscosity. Alternatively,the fluid and cavity within a heat exchanging element can also beconfigured to allow for natural convection of the fluid through thecavity. For example, the absorption of heat may reduce the density ofthe fluid, which may lead to the natural convection of the fluid fromone element, such as element 23, to another element, such as element 24,due to buoyancy effects.

In other embodiments, the thermal contact between the elements of aparticular heat exchanging apparatus can be facilitated viaelectromagnetic waves. For example, a first heat exchanging element,such as element 23, may be separated from a second heat exchangingelement, such as element 24, by a vacuum. The interface between thevacuum and each heat exchanging element may be configured in such a way,that a specified fraction of photons emitted by the first heatexchanging element are absorbed by the second heat exchanging element,and vice versa. For some embodiments, the gap between the first andsecond heat exchanging elements could be made as small as practicalconsiderations will allow. The interface area between the vacuum andeach heat exchanging element could be determined by a specified heatflow rate. The geometry of said interface can also be can be subject toconsiderations regarding the reduction of heat losses during heat flowbetween the first and second heat exchanging elements. The optimalconfiguration of the heat exchanging apparatus depends on theapplication or intended use of the invention. In other embodiments, thegap between a first and second heat exchanging elements need not form avacuum, but could be occupied by a fluid, such as a gas like air, or aliquid like oil. In this case, the thermal contact may not only involvephotons, but also conduction, and, in some embodiments, convection.

In some embodiments, there may be a relative motion between the heatexchanging elements of any one heat exchanging apparatus, such aselement 5 and element 14 of heat exchanging apparatus 6. This may arisefrom relative motion between the fourth reservoir 19 and the secondreservoir 7. This relative motion can be facilitated and controlled byan electric motor, for example. The mechanical connection can beestablished by roller bearings, or magnetic levitation bearings. In thiscase, additional considerations affect the configuration and design ofthe heat exchanging apparatus. For example, an additional objective maybe the reduction of frictional losses associated with the relativemotion. The aforementioned use of electromagnetic waves or a fluid as athermal medium between the heat exchanging elements may be favorable inthat regard. Note that any apparatus which mechanically orelectromagnetically connects a thermal reservoir with another thermalreservoir may also be employed to facilitate a thermal connectionbetween the reservoirs. For example, the related heat exchangingelements may be placed in thermal contact by means of solid materials,such as metals found in roller bearings.

Those skilled in the art will be able to find an appropriate type,configuration, as well as an appropriate method of operation of eachheat exchanging apparatus for the objective and constraints of theintended application.

Any one heat exchanging apparatus may also comprise an apparatus forregulating or modifying the rate of heat flow through the heatexchanging apparatus. Such apparatuses and methods are well known in theart. For instance, the heat flow rate through a heat exchangingapparatus can be regulated by modifying the overall coefficient ofthermal conductivity of the heat exchanging apparatus. This can beaccomplished by placing a material of selected thermal conductivity inthe path of the heat flow between the two thermal reservoirs. Forinstance, two heat exchanging elements of a heat exchanging apparatus,such as elements 23 and 24 of heat exchanging apparatus 20, may beplaced in thermal contact with each other via a third element with aselected thermal conductivity. The thermal conductivity of the thirdelement can be selected in a way in which the overall thermalconductivity of the heat exchanging apparatus is modified in the desiredmanner. Alternatively or concurrently, the area of physical contactbetween two elements of a heat exchanging apparatus can be adjusted tocontrol the heat flow rate. The length of the insulated portion of theheat exchanging apparatus, i.e. the portion connecting the first andsecond heat exchanging elements that is enveloped by insulatingapparatus 15, can also be used to modify the heat flow rate.

In the case in which the heat flow through a heat exchanging apparatusinvolves the forced convection of a fluid within the heat exchangingapparatus, the heat flow rate can be controlled by regulating the flowrate of the fluid, which in turn can be modified by controlling theoperation of the pump responsible for circulating the fluid through theheat exchanging apparatus. In the case in which the fluid involved inthe heat transfer process is subject to natural convection, the flowrate can be modified by regulating the cross-sectional area at asuitable point along the path of the fluid throughout the convectionprocess.

There are numerous ways for controlling the heat flow rate in the casein which there is an exchange of electromagnetic waves between a firstsurface area of a first heat exchanging element and a second surfacearea of a second heat exchanging element of a particular heat exchangingapparatus. For example, the fraction of photons emitted by the firstsurface area which are absorbed by the second surface area can beadjusted. This can be accomplished in several ways. For instance, athird material with a high reflectivity can be placed between the firstand second surface area, such that the third material reflects a portionor all of the photons emitted by the first surface area back towards thefirst surface area, and a portion or all of the photons emitted by thesecond surface area back towards the second surface area. Other methodsfor regulating the heat flow rate for these and other types of heatexchanging apparatuses are well known in the art.

FIG. 1 shows an insulating apparatus 15. One of the criteria forselecting and configuring insulating apparatus 15 may be the ability ofthe material to reduce the unintended heat flow rate from a particularreservoir contained within or enclosed by the insulating apparatus 15,such as the third reservoir 18, to another enclosed reservoir, such asthe fourth reservoir 19, or to an open reservoir, such as the outsideenvironment, or vice versa. In the embodiment shown, insulatingapparatus 15 is a solid material with a low coefficient of thermalconductivity. While explaining the operation of the apparatus shown inFIG. 1, insulating apparatus will be treated as a substantiallyperfectly insulating material. In reality, insulating apparatus 15 maynot be perfectly insulating.

In some embodiments, insulating apparatus 15 may comprise an insidelayer and an outside layer, with the outside layer separated from theinside layer by a vacuum. In other embodiments, the outside layer may beseparated from the inside layer by another suitable material, such as afluid. A vacuum may improve the ability of insulating apparatus 15 tosuppress unintended heat flow. A vacuum or other suitable material inthe space between the outside layer and the inside layer may also beuseful for reducing frictional losses in embodiments involving relativemotion between the outside and inside layer. For instance, the outsidelayer may interface with a reservoir, such as the outside environment orthe second reservoir 7. The inside layer may interface with a differentreservoir, such as the fourth reservoir 19, which may move relative tothe stationary reservoir. Those skilled in the art will be able to finda suitable material, such as a fluid with a low thermal conductivity anda low viscosity.

In the simplified example shown in FIG. 1, material A 1 in the firstreservoir 2 and material B 8 in the second reservoir 7 are gases.Material C 16 in the third reservoir 18, and material D 17 in the fourthreservoir 19 are also gases, which, for simplicity, will be treated asideal gases.

In accordance with the present exemplary embodiment, materials A 1, B 8,C 16, and D 17 are configured to be “thermal media”. The term “thermalmedium” used herein refers to any physical medium which can facilitatethe transport of energy. A thermal medium is therefore not limited tothe aforementioned gaseous embodiments, but can comprise any of a largenumber of different materials or take any of a large number of forms. Athermal medium may be a solid or a fluid, for example. A thermal mediummay be any type of solid, such as a crystal or glass, as well as anytype of fluid, such as a liquid, gas, plasma or ferrofluid. A thermalmedium may also comprise individual sub-molecular particles, such aselectrons or protons. In some embodiments a thermal medium may alsoconsist substantially of photons. In this case the reservoir containingthe thermal medium may be described as a vacuum. In other words, athermal medium may also be modeled as an object capable of emitting orabsorbing electromagnetic waves. Note that a thermal medium may consistof a collection or mixture of different types of materials. For example,one type of material in a thermal medium may be a particular type ofmolecule in gaseous form, such as dinitrogen, while another type ofmaterial in the same thermal medium may be a photon. Note that a thermalmedium may also consist of an assembly of distinct collections of aparticular type or form of material. For example, a portion of a thermalmedium may be a solid such as copper, while another portion may be aliquid such as water, while yet a third portion may be steam, i.e. waterin a gaseous phase. In the context of materials A 1, B 8, C 16, and D17, as well as heat exchanging apparatuses 3, 6 and 20, the terms“material” and “thermal medium” are used interchangeably in this paper,since the associated materials are configured to be thermal media. Notethat this also applies to cases in which a particular thermal medium maynot frequently, commonly, or conventionally be referred to as amaterial. For instance, a photon is a thermal medium, but may notconventionally be referred to as a material. Note that material D 17 maybe one type of material, such as a solid such as a metal such as copperor aluminum, while material C 16 may be another type, such as a gas suchas argon or air. Note that there may be constraints on some of thematerial properties of material D 17 and C 16. These constraints dependon the intended use of the apparatus, as will be explained later.

The heat flow within a particular reservoir, such as the third reservoir18, can take several forms. The heat can be transported within areservoir by thermal conduction, for example. This may apply to ascenario where material D 17 consists of a solid such as copper, forinstance. In the embodiment shown in FIG. 1, heat can be transported vianatural convection, as well as other mechanisms. In other embodiments,forced convection may be employed to facilitate heat flow within aparticular thermal reservoir. For example, a fan may be used tocirculate a fluid within a reservoir. In yet other embodiments, photonsmay be used to transport thermal energy throughout a reservoir. In thiscase, the interior wall of insulating apparatus 15 at the interface to aparticular reservoir may be endowed with a large coefficient ofreflectivity, or with similar properties conducive to the reflection ofphotons, in order to reduce any unintended heat flow rate from thereservoir into insulating apparatus 15.

In FIG. 1 there is a body force per unit mass acting on material C 16 inthe third reservoir 18 and material D 17 in the fourth reservoir 19. Inthis simplified example, the body force is constant in time, as well asconstant in magnitude and direction within the entire volume of, andequal for, each of said reservoirs. The body force is directedvertically downwards, towards the bottom of the page. In theconfiguration shown, this direction is also parallel to the long axis ofthe cross-section of the third reservoir 18. In other embodiments, thebody force need not be distributed uniformly in space, or be constant intime. The body force acts on at least a subset of particles withinmaterial C 16 and D 17. In other words, a subset of particles ofmaterial C 16 and material D 17 are subject to an accelerationcontribution. The term “acceleration contribution” is used todistinguish the contribution of the body force per unit mass to theinstantaneous net acceleration of a particle within a thermal mediumfrom the instantaneous net acceleration per se. There are numerous waysin which such body forces per unit mass can be generated.

One type of such a body force per unit mass is the gravitationalacceleration acting on a thermal medium.

A body force may arise from the existence of a potential field gradient.One such example is the force which arises from the gradient of anelectric potential. For example, the elements of a thermal medium can beconfigured to be electrically charged. In the context of a thermalmedium, the term “elements” refers to the constituent parts of thethermal medium, such as sub-molecular particles, molecules, or adistinct or specified collection of molecules, for example. In the caseof a gas, the molecules could be positively or negatively ionized, forinstance. The thermal medium may also comprise a collection of mobileelectrons. Note that this collection may be contained in a solid, suchas a conductor, or it may be described as a gas. By applying an electricfield within a reservoir, body forces per unit mass can be generated onthe electrically charged elements of the thermal medium inside thereservoir.

For other embodiments it may be impossible or inconvenient to use,procure, or create a thermal medium with mobile electrical charges. Inthis case, elements of the thermal medium may be polarized by applyingan electric field, or these elements may already have an intrinsicpolarization, as in the case of polar molecules, such as dihydrogenmonoxide. When placed in an electric field gradient, these polarizedelements can experience a body force. Note that the magnitude of saidforce depends on the orientation of the polarization axis relative tothe electric field, amongst other parameters. Thus an electric field canbe configured to generate body forces per unit mass on the polarelements in the thermal medium in a reservoir, as well as polarizeelements in the thermal medium, if necessary. The electric field can beapplied in a myriad of ways known in the art.

Magnetism can also be employed to generate body forces. The thermalmedium may comprise diamagnetic, paramagnetic, or ferromagneticelements. When magnetized, the individual elements in the thermal mediummay form magnetic dipoles, or these elements may already have anintrinsic magnetic dipole, such as an electron. When these magneticdipoles are placed in a magnetic field with a non-zero curl or gradient,they can experience a body force. Note that the magnitude of the bodyforce is a function of the orientation of the magnetic dipole relativeto the local magnetic field, amongst other parameters. Thus an externalmagnetic field can be configured to generate body forces per unit masson the magnetized elements in the thermal medium in a reservoir, as wellas magnetize the elements in the thermal medium, if necessary. Themagnetic field can be generated by ferromagnets other at leastinstantaneously magnetized elements, or by an electrical current flowingthrough an electromagnet, amongst other methods known in the art.

The body forces per unit mass may also arise from inertial effects. Forinstance, a reservoir may be subject to an acceleration in an inertialframe. This results an acceleration of the thermal medium relative tothe reservoir. When accelerating a reservoir at a constant rate ofacceleration in an inertial frame in a direction vertically upwardstowards the top of the page in FIG. 1, the thermal medium inside thereservoir will experience an acceleration relative to the reservoir,where the acceleration is directed vertically downwards towards thebottom of the page. Inertial forces can be generated by linearacceleration, i.e. motion of the reservoir along a straight line in theinertial frame. Inertial forces can also be generated by angularacceleration, i.e. motion of the reservoir along a curved path. Ingeneral, inertial forces can be generated by any accelerating motion inan inertial frame. Consider the aforementioned case in which thedepicted apparatus undergoes circular motion in an inertial frame, wherethe radius and angular velocity remain constant. In the embodiment shownin FIG. 1, the axis of rotation could be parallel to and coincident witha horizontal line passing through the centroid of the depicted portionof the cross-section of the first reservoir 2 and the second reservoir7, for example. Note that the centripetal acceleration varies linearlywith radius in this embodiment. If a substantially uniform body forceper unit mass of thermal medium is desired, the depicted apparatus canbe located at a larger radius, where the radial dimension of theapparatus is only a fraction of said radius. For instance, the radiuscan be increased by placing the horizontal axis of rotation furtherupwards towards the top of the page in FIG. 1. In some embodiments, thedirection vector of the axis of rotation can lie anywhere in a planeperpendicular to the plane of the page and intersecting the plane of thepage horizontally. Other embodiments can have different locations andorientations of the axis of rotation, as well as different rotationalvelocities. These parameters may also vary in time. Embodimentsemploying other types of forces or combinations thereof are within thespirit and scope of the invention.

One can define a potential as the integral of the value of the bodyforce per unit mass over a displacement relative to a specifiedreference point. Note that the potential in this context is amathematical construct, and need not have a physical manifestation. Onecan define the position within any thermal reservoir which is subject toa body force per unit mass in terms of the value of a potential at thatposition. For a given potential, there is a set of possible pointswithin the reservoir at which the value of the potential is the value ofthe given potential. In general, this set describes a three dimensionalequipotential surface. For example, consider a simplified case in whicha thermal medium inside a thermal reservoir is subject to a body forceper unit mass, where the body force is uniform in magnitude anddirection throughout the reservoir and constant in time. The thermalreservoir is an isolated system, i.e. closed and perfectly insulated,and has the shape of a cylinder with length L and radius R, forinstance. One can define a Cartesian reference frame, with the z-axisparallel to the length L of the cylinder, and parallel to, and directedin the opposite direction of, the body force per unit mass. The originof the reference frame is the center of the circular area at the top ofthe cylinder, where the “top” is defined relative to the z-axis. In thiscase, the equipotential surfaces are planes perpendicular to the z-axis.A reference point may be defined to be the origin of the referenceframe. The value of the potential at the top of the cylinder istherefore zero, while the value of the potential at the bottom of thecylinder is equal to the negative value of the product of the body forceper unit mass and the length L of the cylinder. The equipotentialsurfaces for other embodiments can be found using similar principles.

Provided is an apparatus and method for facilitating heat flow. Theapparatus comprises a first and second thermal reservoir, where eachreservoir contains a first and second thermal medium respectively, andwhere the first reservoir is at least partially insulated from thesecond reservoir as well as any other reservoir, such as the outsideenvironment, and vice versa. The thermal medium in each reservoir issubject to a body force per unit mass, which, in general, does not havea uniform magnitude or direction for different points in space and maynot be constant in time.

For illustrative purposes, a specific mode of operation of such anapparatus will be considered. In this mode of operation, the body forceper unit mass distribution is assumed to be constant in time, and eachreservoir is assumed to be in thermal equilibrium with its surroundings.The objective during this mode of operation is to establish a differencein temperature between a point A in the first thermal reservoir and apoint D in the second thermal reservoir, where point A and point D arelocated on the same equipotential surface defined by a first potentiallevel.

In accordance with the invention, at least one heat exchanging apparatusis configured to place a point B in the first thermal medium intothermal contact with a point C in the second thermal medium. Byconvention, point B and point C are located on the same equipotentialsurface defined by a second potential level. The second potential levelmay be larger or smaller than, but not equal to, the first potentiallevel. Since this mode of operation assumes a thermal equilibrium, thetemperatures at point B and point C are identical. Note that theexistence of said heat exchanging apparatus is a matter of definition.The definition of the first or second thermal media can be extended toencompass the heat exchanging apparatus. This approach may be favorablein embodiments in which a distinct heat exchanging apparatus is notreadily identified. In these instances, the thermal media and reservoirsmay be defined in a way in which a point B and a point C coincide.

In accordance with the invention, the defining material properties ofthe first thermal medium within the first reservoir are configuredrelative to the defining material properties of the second thermalmedium within the second reservoir in a way in which the change intemperature, or some other specified material property of interest,between points A and B in the first reservoir and between points D and Cin the second reservoir is not equal. The “defining material properties”are defined as the properties of a thermal medium which determine thechange of the material properties of interest for a given change inpotential for a given thermal medium. As a result of the identicaltemperatures at point B and C and a difference in the change intemperature between points A and B as well as the change in temperaturebetween points D and C, the aforementioned objective is met.

Note that the extent of a thermal reservoir or the definition of theboundary between the first and second thermal medium is a matter ofdefinition, and not limited to the geometry or configuration of aparticular apparatus, or a discontinuity in the type of materialoccupying a given region in space. As mentioned previously, a thermalmedium may comprise many different types of materials, where thematerials may exist as a mixture, or as an assembly of distinctmaterials or distinct phases of the same material. Along varyingpotential levels, a particular thermal medium may consist of differenttypes of material. For example, a thermal medium may be a solid such ascopper for a certain range of potential levels, and gas such as airalong a different range of potential levels within the associatedreservoir.

The aforementioned principles of operation will now be described in thecontext of the simplified example embodiment shown in FIG. 1. The firstthermal medium is material C 16 in the third reservoir 18, and thesecond thermal medium is material D 17 in the fourth reservoir 19.Materials C 16 and D 17 are ideal gases, insulated by insulatingapparatus 15. For simplicity, these reservoirs are assumed to beperfectly insulated along the length of the reservoirs. Recall thatthere is a body force per unit mass acting on material C 16 in the thirdreservoir 18 and material D 17 in the fourth reservoir 19, where, forsimplicity, the body force per unit mass is equal for both reservoirs,constant in time and constant in direction and magnitude throughout eachreservoir, and directed vertically downwards. One can define a height z,which decreases linearly along the direction vector of the body forceper unit mass, i.e. in the vertically downwards direction, towards thebottom of the page. Since the body force per unit mass is constant, allpoints within a thermal medium at the same height z within a reservoirlie on the same equipotential surface.

In the operating mode mentioned above, all four reservoirs shown in FIG.1 are assumed to be in thermal equilibrium, i.e. there is a zero heatflow rate between any two reservoirs. In such an operating mode, theobjective of the depicted apparatus is the establishment of a differencein temperature between station 10, i.e. point A, in the third reservoir18 and station 11, i.e. point D, in the fourth reservoir 19. Note thatpoint A and point D are located on the same equipotential surfacedefined by a first potential level. This is evident from the fact thatthe height z of station 10 is equal to height z of station 11.

In the aforementioned equilibrium configuration, heat exchangingapparatus 20 ensures that the temperature at station 21, i.e. point B,is equal to the temperature at station 22, i.e. point C. As before, theposition of stations 21 and 22 along height z is identical, and points Band C are located on the same equipotential surface defined by a secondpotential level. In this case, the second potential level is lower thanthe first potential level.

Due to the thermal insulation and the body force per unit mass, theproperties of the ideal gas inside the third reservoir 18 and the fourthreservoir 19 vary adiabatically along the vertical length of thereservoir. Thus, as the height z of an element of a material in such areservoir, such as material C 16 in the third reservoir 18, decreasestemperature of the element increases. In this simplified model, thetemperature increases linearly as height z decreases within thereservoir. In this case, the material property of interest is thetemperature, while the defining material property for an ideal gas isthe specific heat capacity at constant pressure. For other embodiments,such as a scenario in which a material in a reservoir, such as materialD 17 in the fourth reservoir 19, is not an ideal gas, but a solid, othermaterial properties may affect the change in temperature of the materialalong the height z of the associated reservoir. In the apparatus in FIG.1, the configuration of the defining material properties comprisesselecting as material C 16 an ideal gas with a specific heat capacity aconstant pressure which is different to that of a selected material D17. The sign and the magnitude of the difference in the definingmaterial properties between materials C 17 and D 17 is determined by thedesired sign and magnitude of the difference in the change in thematerial properties of interest, i.e. the temperature. In FIG. 1, thechange in the material properties of interest is measured betweenstations 10 and 21 for material C 17, and between stations 11 and 22 formaterial D 17.

Due to the difference in the defining material properties betweenmaterial D 17 and C 16, the temperature change between stations 10 and21 is not equal to the temperature change between stations 11 and 22. Itfollows, therefore, that the temperature at station 10 is not equal tothe temperature at station 11. Thus the objective is met. Note that heatexchanging apparatus 3 ensures that the temperature at station 10 isequal to the temperature at station 9 in thermal equilibrium, and heatexchanging apparatus 6 ensures that the temperature at station 11 isequal to the temperature at station 12 in thermal equilibrium. Thus, thetemperature at station 9 is also not equal to the temperature at station12 in thermal equilibrium. The apparatus shown in FIG. 1 will have atendency to restore this equilibrium configuration when there are slightdeviations from this equilibrium configuration.

Consider a configuration in which the temperature at station 9 is lowerthan the temperature at station 12 when all four depicted reservoirs arein thermal equilibrium. In this case the temperature at station 10 isequal to the temperature at station 9, and the temperature at station 11is equal to the temperature at station 12. The specific heat capacity atconstant pressure of material C 16 is lower than the same of material D17. For example, material C 16 may be argon, while material D 17 may beair. Given that material C 16 and material D 17 are in thermalequilibrium at stations 21 and 22, the temperature at station 10 must belower than the temperature at station 11.

This scenario is shown in FIG. 2. The y-axis of the plot in FIG. 2 isthe height z. Note that the units of height z are arbitrary in thiscase. Line 25 indicates the variation of the body force per unit massalong height z, where the body force per unit mass has been normalizedby its value at the point where the height z is zero. Similarly, line 26portrays the variation of the normalized temperature of material D 17 inthe fourth reservoir 19 along height z, where the temperature has beennormalized by its value at station 11. Line 27 illustrates the variationof the temperature of material C 16 in the third reservoir 18 alongheight z, where the temperature has also been normalized by the value ofthe temperature of material D 17 at station 11. As shown in FIG. 1 andFIG. 2, station 11 describes the state of material D 17 at the pointwhere the height z is zero, while station 22 designates the state at theminimum height z. Stations 10 and 21 label the corresponding states ofmaterial C 16.

In this configuration, the apparatus shown in FIG. 1 can be used as anartificial heat sink for the first reservoir 2. Consider the case inwhich the first reservoir 2 is the interior of a refrigeration unit, andmaterial A 1 comprises the air contained in the interior of therefrigeration unit, as well as other materials, such as the items to berefrigerated. The second reservoir 7 may be the room in which therefrigeration unit is located, and material B 8 may be the air containedin that room. Consider an initial configuration in which all fourreservoirs are in thermal equilibrium, similar to the scenario shown inFIG. 2. Now consider an instantaneous increase in temperature in thefirst reservoir 2, which may arise from the placement of an item to becooled in the refrigeration chamber. The departure from the initialequilibrium condition results in an instantaneously larger temperatureat station 9 compared to station 10. As a result, heat flows throughheat exchanging apparatus 3, which in turn increases the temperature atstation 10. Similarly, this increase in temperature at station 10propagates through the thermal medium C 16, heat exchanging apparatus20, thermal medium D 17, and heat exchanging apparatus 6 to station 12.This heat flow from the first reservoir 2 to the second reservoir 7 viathe third reservoir 18 and the fourth reservoir 19 will continue until athermal equilibrium is reached once more.

In another embodiment, the apparatus shown in FIG. 1 may be used as anartificial heat source for the first reservoir 2. Consider aconfiguration in which the temperature at station 9 is higher than thetemperature at station 12 when all four depicted reservoirs are inthermal equilibrium. As before, the temperature at station 10 is equalto the temperature at station 9, and the temperature at station 11 isequal to the temperature at station 12. In this embodiment, the specificheat capacity at constant pressure of material C 16 is larger than thesame of material D 17. For example, material C 16 may be helium, whilematerial D 17 may be air. Given that material C 16 and material D 17 arein thermal equilibrium at stations 21 and 22, the temperature at station10 must be larger than the temperature at station 11. This scenario isshown in FIG. 3. Line 28 illustrates the variation of the temperature ofmaterial C 16 in the third reservoir 18 along height z, where thetemperature has also been normalized by the value of the temperature ofmaterial D 17 at station 11. The operation of the apparatus shown inFIG. 1 as an artificial heat source is similar in principle to theaforementioned operation of the apparatus as an artificial heat sink.

Note that for some embodiments, there may be a negligible change intemperature between station 21 and station 10. This may be the case forsome gases with a very large specific heat capacity at constantpressure, or for some liquids and some solids. For instance, element 23of heat exchanging apparatus 20 may be rigidly connected to element 4 ofheat exchanging apparatus 3 by a solid material C 16, where the solidmaterial may be identical to the material of heat exchanging elements 23and 4.

FIG. 4 shows another exemplary embodiment. In this case the body forceper unit mass is generated by means of centripetal acceleration of amaterial C 34 inside a third reservoir 33, which is confined by aninside insulation apparatus 56. A material D 36 inside a fourthreservoir 35, which also confined by inside insulation apparatus 56 issubject to the same body force per unit mass distribution as material C34. Note that the magnitude and direction of the body force per unitmass is not constant throughout reservoirs 33 and 35, but is insteaddetermined by the local value of the centripetal and Coriolisaccelerations, amongst other possible sources of acceleration. As inFIG. 1, there is a first reservoir 29, comprising a material A 30, and asecond reservoir 31, comprising a material B 32. A heat exchanger 37 isconfigured to exchange heat between the first reservoir 29 and the thirdreservoir 33. In order to transfer heat from one element of the heatexchanger in the first reservoir to another element of the heatexchanger in the third reservoir, electromagnetic waves are exchangedbetween an outside plate 40 and an inside plate 41. The plate may bemade of a solid material specially selected and configured for a givendesired heat flow rate. The material could be a metal such as copper.Heat exchanger 42 is configured similarly and performs a similarfunction, albeit for the fourth reservoir 35 and the second reservoir31. Stations 9, 10, 21, 22, 11, and 12 in FIG. 1 correspond to stations50, 52, 53, 55, 54, and 51 in FIG. 4, respectively. Heat exchangingapparatus 47 is configured to facilitate heat flow between the thirdreservoir 33 and the fourth reservoir 35, similar to heat exchangingapparatus 20 in FIG. 1. The apparatus shown in FIG. 4 is cylindricallysymmetric about the axis of rotation 64 of the inside insulatingapparatus 56. Inside insulating apparatus 56 is separated from anoutside insulating apparatus 57 by a gap 65 which can be described as avacuum in this embodiment. In other embodiments, the gap may comprise adifferent material, such as a fluid. The inside insulating apparatus 56contains the third reservoir 35 and the fourth reservoir 35, and isconfigured to rotate about axis 64 within outside insulating apparatus57. The mechanical support of inside insulating apparatus 56 is providedby magnetic levitation apparatus in this particular embodiment. In otherembodiments, conventional mechanical bearings, such as roller bearings,or fluid bearings may be used. The magnetic levitation apparatuscomprises axial inside magnets 61 and axial outside magnets, as well asradial inside magnets 63 and radial outside magnets 62 for stability. Anelectric motor with a stator 59 and a rotor 58 provides the torquerequired for angular acceleration and deceleration, as well as forovercoming any sources of friction. In order to transfer angularacceleration to the materials contained within reservoirs 35 and 33,there may be baffles arranged radially within these reservoirs. In otherwords, there may be several circumferentially arranged chambers. In thiscase, each chamber can be considered a reservoir in its own right.Alternatively, the angular acceleration can also be transferred usingviscous friction between the walls of the reservoirs and the materialswithin the reservoirs. The operation of the apparatus shown in FIG. 4follows the same principles and concepts elucidated in the context ofFIG. 1.

FIGS. 6A-6B are a cross-sectional view of one example apparatus showntogether with a plot of normalized material properties as a function ofposition along a length of the apparatus at a particular point in time.

The example apparatus comprises a fully enclosed chamber 117, whichcontains a working material, which can be a fluid or solid, or acombination thereof. The working fluid can be a liquid, such as water,or a gas, such as air. The working fluid can also be a mixture of vaporand gas, such as a combination steam and liquid water. The working fluidor solid can be any suitable material, where suitability is a functionof material properties, which can be evaluated by those skilled in theart. In the depicted example embodiment, the working fluid is an idealgas. Chamber 117 forms a closed system around the working material. Inother embodiments the working material and the apparatus employing itcan form an open system.

Chamber 117 is isolated from the environment by an insulating material110, which prevents any unintended heat exchange between the workingmaterial in chamber 117 and the outside environment, in the ideal case.

Elements of the outside environment are able to do work on the workingmaterial via a work exchange apparatus 107. Such elements could compriseseparate actuators, such as an electric motor, for example. Theactuators, as well as their associated energy supply or reservoir, arenot shown for simplicity. Such apparatuses are well known in the art. Inthis particular embodiment, work exchange apparatus 107 is a piston,with head 109 and circular shaft 108. In other embodiments, workexchange apparatus 107 can take other forms, such as an axial turbine ornozzle. These examples are particularly suitable in the case where theworking material and the apparatus employing it form an open system, forinstance. Work exchange apparatus 107 is furthermore insulated in orderto prevent or minimize any unintended heat exchange between the workingmaterial in chamber 117 and the outside environment.

Piston head 109 features a surface in contact with the working material,as well as an opposing surface connected to shaft 108. In the depictedembodiment the opposing surface is in contact with the outside material118. In other embodiments, the opposing surface is isolated from thesurrounding material 118 by an extension of the insulating material 110,for example. The volume thus created by the opposing surface and theextension of the insulating material is denoted the “second chamber”.The second chamber and outside material 118 would be part of theaforementioned outside environment. In some embodiments, the secondchamber is evacuated. This could improve the effectiveness of theinsulation and reduce the energy consumed by friction during the motionof the piston. In other embodiments, the second chamber is pressurized,where the pressure is independent of the pressure of the surroundingmaterial. The pressure of the second chamber could be modified in a wayin which improvements in efficiency of the actuator operating the workexchange apparatus 107 are attained. For example, the pressure of thesecond chamber can be controlled in a way in which the average forcebeing exerted by the actuator on the working material in chamber 117during one thermodynamic cycle is reduced or substantially zero. Thiscould reduce the average power consumption of the actuator.Alternatively, this function could be performed by a separate apparatus,such as an adjustable spring which is configured to apply a desiredaverage force on the piston over one cycle.

At location 119 in chamber 117 there is a first inside heat exchangingapparatus 112. Similarly, at location 120 in chamber 117 there is asecond inside heat exchanging apparatus 115. There is also a firstoutside heat exchanging apparatus 111 and a second outside heatexchanging apparatus 114. In the depicted example, the heat exchangingapparatuses are embodied by a coil with a high thermal conductivity. Anexample material for the coil could be copper. In other embodiments, theheat exchanging apparatus can comprise a second working fluid speciallyselected for heat exchange. The heat exchanging apparatus could alsocomprise a pump or other actuator for moving the second working fluidthrough the heat exchanging apparatus in order to facilitate a higherrate of heat transfer between the heat exchanging apparatus and theworking material or outside material 118. The second working fluid neednot be contained by the heat exchanging apparatuses in a closed system.For example, the outside material 118 can be employed as the secondworking fluid, which is allowed to enter and exit the heat exchangingapparatuses in an open thermodynamic system. The second working fluidcan pass through the heat exchanging apparatuses via natural or forcedconvection. The heat exchanging apparatuses can also be speciallyadapted for irradiative heat transfer to and from outside material 118,or to and from the working material. A vast number of alternative typesand configurations of such a heat exchanging apparatuses are known inthe art. The first and second heat exchanging apparatuses need not beidentical.

The connection between the outside heat exchanging apparatus and thecorresponding inside heat exchanging apparatus can be modified, suchthat the heat flow between these two apparatuses can be controlled. Inthe depicted embodiment, each outside heat exchanging apparatus can bedisconnected or insulated from the corresponding inside heat exchangingapparatus. As shown, an insulating gap 116 can be formed between thesecond outside heat exchanging apparatus 114 and the second inside heatexchanging apparatus 115. Similarly, as shown in FIG. 7B, an insulatinggap 113 can also be formed between the first outside heat exchangingapparatus 111 and the first inside heat exchanging apparatus 112. Inthis embodiment, therefore, no heat is able to flow between the outsideand corresponding inside heat exchanging apparatus when these two heatexchanging apparatuses are disconnected. In other embodiments, theamount of heat flow between the outside and corresponding inside heatexchanging apparatuses is modified without necessarily achieving acomplete disconnection or insulation between these two heat exchangingapparatuses. The heat flow can be modified in numerous ways. Forexample, the surface area of an outside heat exchanging apparatus can bereduced in order to reduce the rate of heat transfer between the workingmaterial inside chamber 117 and the outside material 118. In the case inwhich a second working fluid is employed by a heat exchanging apparatus,the flow rate of the second working fluid through the heat exchangingapparatus can be modified in order to control the rate of heat transferbetween chamber 117 and the outside material 118. Alternatively, asecond material with a different thermal conductivity can be insertedinto, or removed from, the thermal circuit connecting the outside andcorresponding inside heat exchanging apparatuses. For example, when thethermal conductivity of the second material is lower than the thermalconductivity of the material used in the heat exchanging apparatuses,the rate of heat transfer between chamber 117 and outside material 118is reduced when the second material is inserted. There are a largenumber of other configurations and methods available for modifying andcontrolling the heat flow of a heat exchanger for a given temperaturedifference between two thermal reservoirs, i.e. the working material andoutside material 118.

Outside material 118 can also be any type of material, such as a gas,liquid, or solid. For example, the outside material can be the contentsof a thermal reservoir which is to be cooled, as exemplified by theinner chamber of a refrigerator. When the depicted apparatus is operatedas an artificial heat source, outside material 118 is the thermalreservoir which is to be heated. Outside material 118 may also bemodeled as an object capable of emitting or absorbing electromagneticwaves.

In accordance with exemplary embodiments, a force per unit mass isacting on the working material in chamber 117 and the force may be abody force or a mechanical force. In FIGS. 6A-6B, the force is a bodyforce per unit mass. In a simplified example, the body force per unitmass is constant in position and time throughout chamber 117. Thisconfiguration is shown in FIGS. 6A-6B, where the body force per unitmass is directed vertically downwards towards the bottom of the page.Note that this description of the direction is relative to the pageonly, and is unrelated to the orientation of the apparatus relative toan inertial frame, such as an inertial frame located on the surface ofthe earth. The plot on the left side of FIGS. 6A-6B, illustrates theresulting variation of thermodynamic properties of the working materialalong the length “z” of chamber 117, where the length is measuredparallel to and indicated by the y-axis of said plot. In this plot, line104 indicates the variation of the body force per unit mass along lengthz, where the body force per unit mass has been normalized by its valueat the point where the length z is equal to zero. Similarly, line 103portrays the variation of the normalized specific volume along length z,while line 105 illustrates the variation of the normalized temperature,and line 106 the variation of the normalized pressure along length z. Inthis example, the first outside heat exchanging apparatus 111 isconnected to the first inside heat exchanging apparatus 112. Thereforethe temperature of the working material inside chamber 117 at location119 is substantially equal to the temperature of the outside material118 at this location. In the depicted examples, the temperature ofoutside material 118 is uniform in space and time, for simplicity. Sincethe body forces acting on the working material are directed towards thebottom of the page in FIGS. 6A-6B, the working material is compressed asthe length z is decreased. Thus the pressure rises and the specificvolume decreases. The insulating material 110 around chamber 117 ensuresa substantially adiabatic compression in this case, resulting in anincreased temperature at location 120 compared to location 119, asindicated by line 105.

In other embodiments, the walls may not be perfectly insulating,resulting in a distribution of thermodynamic properties which lies inbetween the adiabatic case and the isothermal case. In otherembodiments, the force need not be constant in space or time in chamber117.

In other embodiments, the force generation apparatus comprises the workexchange apparatus. In other words, the force generation apparatus ormechanism can be configured relative to chamber 117 in a manner in whichthe force can be made to vary with time, such that work can be done onand by the working material. For example, during a portion of timeduring which the purpose of the work exchange apparatus is to compressthe working material, the force inside chamber 117 can be increased.Throughout the compression process work will be done by the body forceactuation mechanism on the working material. An expansion processinvolving the work exchange apparatus would follow similar principles ofoperation.

As mentioned, body forces can be generated by a variety of methods. Onetype of body force is the gravitational force acting on the workingmaterial.

Another type of body force is an inertial force, which can be generatedby accelerating the depicted apparatus, comprising chamber 117 andinsulating material 110, in an inertial reference frame. Whenaccelerating the apparatus at a constant acceleration in an inertialframe in a direction vertically upwards towards the top of the page, theworking material inside chamber 117 will experience an apparentacceleration relative to chamber 117 and insulating material 110, wherethe apparent acceleration is directed vertically downwards towards thebottom of the page. Inertial forces can be generated by linearacceleration, i.e. motion of the apparatus along a straight line in theinertial frame. Inertial forces can also be generated by angularacceleration, i.e. motion of the apparatus along a curved path. Ingeneral, inertial forces can be generated by any accelerating motion inan inertial frame. Consider the aforementioned embodiment in which thedepicted apparatus undergoes circular motion in an inertial frame, wherethe radius and angular velocity remain constant. In the embodiment shownin FIGS. 6A-6B, the axis of rotation could be parallel to and coincidentwith the centerline of a circular piston shaft 108, for example. Notethat the centripetal acceleration varies linearly with radius in thisembodiment. If a substantially uniform body force per unit mass ofworking material is desired, the depicted apparatus can be located at alarger radius, where the radial dimension of the apparatus is only afraction of said radius. For instance, the radius can be increased byplacing the axis of rotation further upwards towards the top of the pagein FIGS. 6A-6B. In other embodiments, the direction vector of the axisof rotation can have components parallel to the plane described by thevector pointing perpendicularly out of the page containing FIGS. 6A-6B,as well as the vector parallel to the centerline of piston shaft 108.Other embodiments can have different locations and orientations of theaxis of rotation, as well as different rotational velocities. Theseparameters may also vary in time.

A further type of body force is an electromagnetic force. For example,the elements of the working material in chamber 117 can be configured tobe electrically charged. In the context of a material, the term“elements” refers to the constituent parts of the material, such assubatomic particles, atoms, molecules, or a distinct or specifiedcollection of molecules, for example. In the case of a gas, the atoms ormolecules could be positively or negatively ionized, for instance. Theworking material may also comprise a collection of mobile electrons.Note that this collection may be contained in a solid, such as aconductor, or it may be described as a gas. By applying an electricfield within chamber 117, body forces can be generated on theelectrically charged elements of the working material. When at least asubset of these elements are mobile in the sense that they can moverelative to each other and be compressed, a pressure and temperaturegradient can be generated inside chamber 117 in accordance with theaforementioned principles.

Embodiments employing other types of forces or combinations thereof arewithin the spirit and scope of the invention. In one embodiment of theinvention, there is provided a method for exchanging heat between tworeservoirs, where the range of relative average temperatures of thereservoirs for which heat can be made to flow in a specified directionis increased compared to heat exchangers in the prior art. In thefollowing method, the first reservoir is denoted the “working material”while the second reservoir is denoted the “external reservoir”. Themethod comprises: subjecting the material in at least one of the tworeservoirs, defined as the working material, to a body force per unitmass, such that a difference in temperature can be generated between atleast two different points in the working material, where the two pointscan are distinct in space or time; enclosing at least a portion of theworking material with an insulating material, where the enclosure andthe insulating material are configured to inhibit or reduce heat flowbetween the working material and the external reservoir in an unintendeddirection, as well as facilitate the heat transfer between the externalreservoir and the working material in the intended direction, where thefacilitation can comprise thermally connecting a point in the workingmaterial as well as a point in the external reservoir, such that thetemperature difference between these two points allows heat to flowbetween the two reservoirs in the intended direction, where the thermalconnection can comprise placing the two reservoirs in physical contactat these two points, where physical contact can refer to electromagneticradiation emitted by one reservoir to be absorbed by the other, wherethe two points may or may not be substantially coincident, or it canrefer to individual material elements coming into direct contact toallow thermal conduction to take place, where the two points aresubstantially coincident, or it can refer to the exchange of materialbetween the reservoirs in a convection process, or placing at least oneheat exchanging apparatus between the two points, where the heatexchanging apparatus is configured to enable the heat transfer betweenthe external reservoir and the working material in the intendeddirection, where the two points may or may not be substantiallycoincident. Note that the aforementioned external reservoir can also besubjected to forces in a similar fashion as the working material. Thiscould further increase the range of relative average temperaturesbetween the reservoirs for which heat can be made to flow between thereservoirs in a specified direction. In some embodiments, the differencein the average temperature of a heat source and the average temperatureof a heat sink can be less than or equal to zero. This method can beemployed to operate an artificial heat sink or artificial heat source,for example. As shown in the drawings and as will be described in thefollowing paragraphs, said method can also be applied to the operationof a heat pump, such as a refrigerator, or heat engine.

Note that in the case in which the external reservoir is in physicalcontact with the working material, the material properties of theexternal reservoir and working material may need to be speciallyconfigured. For example, when placed in direct contact, the pressure ofthe external reservoir at the location of contact should match thepressure of the working material, if a steady equilibrium configurationis desired. If diffusion of the two reservoirs is to be avoided orreduced, provisions can be made. For example, the material of onereservoir could be in a different phase than the material of the other.One reservoir could contain solid material, while the other containsgaseous material, for instance.

FIG. 5 is a plot of pressure versus specific volume, which indicates thevariation of said parameters at different locations within one exampleapparatus and at different points in time during one example method ofoperation.

In FIGS. 7A-7H a cross-sectional view of the example apparatus of FIGS.6A-6B, is shown in different configurations in accordance with differentpoints in time during the example method of operation shown in FIG. 5.

In FIG. 7A, the example apparatus of FIGS. 6A-6B, is shown in aconfiguration that can be described as follows. The first outside heatexchanging apparatus 111 and the first inside heat exchanging apparatus112 form a closed thermal circuit, allowing heat exchange betweenoutside material 118 and working material in chamber 117. Thethermodynamic properties of the working material are constant in time inthe configuration shown in FIG. 7A, and the outside material and workingmaterial are in thermal equilibrium. Thus, the temperature of theworking material at location 119 in FIGS. 6A-6B, is equal to thetemperature of outside material 118. The thermodynamic state 81 of theworking material at location 119 in FIGS. 6A-6B, is indicated in FIG. 7Aand shown in FIG. 5. In this configuration, an insulating gap 116 ispresent between the second outside heat exchanging apparatus 114 and thesecond inside heat exchanging apparatus 115. A uniform body force perunit mass is acting on the working material in chamber 117, where thebody force is directed vertically downwards towards the bottom of thepage. In this simplified example, insulating material 110 prevents anyexchange of heat between the working material and outside material 118.The insulating material 110 also spatially confines the workingmaterial, i.e. it is exerting a pressure on the working material. Inother embodiments, the working material can be confined by action ofbody forces, or interaction with other elements of the working material.As a result, the working material is compressed along the negativelength z of chamber 117 as indicated in the plot on the left of FIGS.6A-6B. Since no heat is exchanged with the environment, the compressioncan be modeled as an adiabatic compression, resulting in an increase intemperature along the negative length z, as shown in FIGS. 6A-6B. Thisadiabatic compression is also illustrated by the light dashed line 96 inFIG. 5. The thermodynamic state 85 of the working material at location120 in FIGS. 6A-6B, is shown in FIG. 7A and shown in FIG. 5. The averagethermodynamic state 89 of the entire working material enclosed inchamber 117 in the configuration shown in FIG. 7A is also shown in FIG.5. The piston of work exchange apparatus 107 is in a retracted position,as shown.

In FIG. 7B, the equilibrium configuration shown in FIG. 7A has beendisturbed by closing insulating gap 116, allowing the second outsideheat exchanging apparatus 114 and the second inside heat exchangingapparatus 115 to form a closed thermal circuit. The first outside heatexchanging apparatus 111 has also been disconnected from the firstinside heat exchanging apparatus 112 with insulating gap 113. In theconfiguration shown in FIG. 7A the thermodynamic state 85 featured ahigher temperature than thermodynamic state 81, which featured the sametemperature as outside material 118. Therefore, following theelimination of insulating gap 116, there is an instantaneous temperaturedifference between the working material at state 85 at location 120 andoutside material 118. As indicated by “QOUT”, heat will flow from theworking material to outside material 118 until a new equilibriumconfiguration is reached.

FIG. 7C illustrates the new equilibrium configuration. In thisparticular example it is assumed, for simplicity, that the temperaturechange of outside material 118 is negligible throughout this process.This would be a valid assumption when there is a large ratio of the massof outside material 118 to the mass of the working material, or whenthere is an external energy source or sink regulating the internalenergy of outside material 118. In other embodiments, there may be anon-negligible change in temperature of outside material 118 throughoutone cycle. This would be desirable when the apparatus is operated as anartificial heat source or sink. Similar to the configuration in FIG. 7A,the temperature of thermodynamic state 86 is now equal to thetemperature of outside material 118. In FIG. 5, this is illustrated bythe fact that state 86 and state 81 lie on isothermal line 94. Due tothe action of the body forces, and the temperature boundary conditionprovided by thermodynamic state 86, the temperature at thermodynamicstate 82 is lower compared to state 86. Adiabatic line 97 illustratesthe variation of the thermodynamic properties between state 86 and state82 along length z of the apparatus. Note that the position of pistonhead 109 is unchanged in FIGS. 7A-C. Since the working material has lostthermal energy without a change in volume, the average pressure andtemperature of the working material in chamber 117 have been reducedwhile the average specific volume has remained constant. The new averagethermodynamic state 90 is therefore connected by a vertical line to theprevious average thermodynamic state 89 in FIG. 5. In other embodiments,this line need not be vertical, but can have any other orientation, suchas a horizontal orientation.

In FIG. 7D work exchange apparatus 107 is employed to do work on theworking material, where the work is indicated by “WIN”. In thisparticular embodiment, piston head 109 is employed by an actuator tocompress the working material. Note that the configuration of the firstand second heat exchanging apparatuses is unchanged compared to FIGS.7B-7C. Therefore any increase in temperature of the working material asa result of work being done on it leads to an increase in the rate ofheat flow from the working material through the second inside andoutside heat exchanging apparatuses 115 and 114 to outside material 118,as indicated by “QOUT”. The rate of work input into the working materialis controlled in such a manner, that it substantially equals the rate ofheat flow from the working material to outside material 118 at allinstants of time during the compression. In this case, the compressionwould be isothermal. In other embodiments, the compression need not beisothermal, as will be explained later.

FIG. 7E illustrates the new equilibrium position once work exchangeapparatus 107 is no longer doing work on the working material. As inFIGS. 7C-7D, the temperature at state 87 is equal to the temperature ofoutside material 118. In this embodiment, the temperature at state 83 issubstantially equal to the temperature at state 82. Isothermal line 95connects state 82 and state 83. The new average thermodynamic state 91is also shown in FIG. 5. Adiabatic line 98 describes the variation ofthe thermodynamic properties between state 83 and state 87 along lengthz of the apparatus. Note that the temperature at state 83 is lower thanthe temperature at state 87, and hence the temperature of outsidematerial 118.

In FIG. 7F the equilibrium configuration shown in FIG. 7E has beendisturbed by closing insulating gap 113, which allows the first outsideheat exchanging apparatus 111 and the second inside heat exchangingapparatus 112 to form a closed thermal circuit. The second outside heatexchanging apparatus 114 has also been disconnected from the secondinside heat exchanging apparatus 115 by insulating gap 116. Due to theinstantaneous temperature difference between the working material atstate 83 at location 119 and outside material 118, heat will flow fromoutside material 118 to the working material to until a new equilibriumconfiguration is reached. The heat flow is indicated by “QIN”.

FIG. 7G illustrates the new equilibrium configuration. The temperatureat state 84 is now equal to the temperature of outside material 118.Adiabatic line 99 illustrates the variation of the thermodynamicproperties between state 84 and state 88 along length z of theapparatus. Note that the position of piston head 109 is unchanged inFIGS. 7E-7G. The new average thermodynamic properties 92 are indicatedin FIG. 5.

In FIG. 7H the working material does work on work exchange apparatus107, where the work is indicated by “WOUT”. Note that the actuatoroperating the work exchange apparatus 107 is configured to be able to dowork on the working material, as well as extract work from the workingmaterial. Thus, the actuator and its associated energy reservoir isconfigured to extract or recover energy from the work done by theworking material on work exchange apparatus 107. Following similarprinciples of operation described in the context of FIG. 7D, theexpansion process shown in FIG. 7H and FIG. 5 is isothermal. Thus anydecrease in temperature of the working material as a result of itsexpansion results in an increase in the rate of heat flow from outsidematerial 118 through the first outside and inside heat exchangingapparatuses 111 and 112 into the working material, as indicated by“QIN”. The thermodynamic properties of the working material at location120 throughout the isothermal expansion are described by isothermal line93 in FIG. 5.

Once piston head 109 has reached its original position, the motion ofthe piston can be stopped. The new equilibrium configuration would thenbe identical to the initial configuration shown in FIG. 7A. Thus onecomplete, repeatable thermodynamic cycle has been described. Theaforementioned processes which form the cycle can also be carried out inreverse order.

Throughout this cycle, the thermodynamic properties of the workingmaterial at location 120 are described by bold dashed line 102 in FIG.5. The thermodynamic properties of the working material at location 119are described by bold dotted line 100 in FIG. 5. The averagethermodynamic properties of the working material in chamber 117 aredescribed by bold line 101.

Note that the aforementioned isothermal compressions or expansions neednot be isothermal. They can be adiabatic, for example. In the adiabaticcase, the shape or configuration of the thermodynamic properties shownin FIG. 5 will have to be changed or adapted to a new shape. Forexample, the temperature at the corresponding state 81 of the new shapemay be configured to be lower than the corresponding temperature of theoutside material, while temperature at the corresponding state 84 of thenew shape can be less than or equal to the temperature of thecorresponding outside material. This would ensure a closed line similarto line 100 in FIG. 5. The other closed lines shown in FIG. 5 can beadapted accordingly in the aforementioned adiabatic case.

In FIG. 5, the values of the pressure and specific volume shown on theaxes are arbitrary and only selected to provide an example. They are notintended to limit the scope of the invention to a particular type offluid or to a particular range of pressures of specific volumes.

FIG. 8 is a plot of material properties for one example embodimentduring one example method of operation. The horizontal x-axis 167denotes the specific volume of the working material in question, and thevertical y-axis 168 denotes the pressure of the working material. Notethat the units shown are arbitrary and included only for the sake ofexample, and are not intended to limit the scope of the invention to aparticular method of operation or type of working material.

FIG. 8 shows a first cycle and a second cycle. The first cycle comprisesan adiabatic compression 151 between a first station 150 and a secondstation 155, an isobaric expansion 152 with heat addition between secondstation 155 and third station 156, an adiabatic expansion 153 betweenthird station 156 and fourth station 157, and an isobaric compression154 with heat removal between fourth station 157 and a fifth station,which is identical to first station 150. In some embodiments, firststation 150 describes the properties of a working material in the freestream, i.e. at ambient pressure and specific volume, and fourth station157 approximately describes the properties of a working material at theoutlet or the exhaust of a thermodynamic apparatus. The isobariccompression 154 can thus occur in the wake, i.e. downstream, of anembodiment of the invention. In other embodiments, the first cycle canbe a closed cycle. Note that the first cycle is similar to aconventional Brayton cycle. In other embodiments, the first cycle can besimilar to an Otto cycle. In other embodiments, the first cycle can besimilar to a Diesel cycle. A wide variety of different shapes or formsof the first cycle are readily conceivable. For example, the compressionbetween station 150 and station 155 can be isothermal instead ofadiabatic.

The second cycle comprises an adiabatic expansion 159 between a firststation 150 and a second station 163, an isobaric compression 160involving heat removal between second station 163 and third station 164,an adiabatic compression 161 between third station 164 and fourthstation 165, and an isobaric expansion 162 between fourth station 165and a fifth station, which is identical to first station 150. In someembodiments, first station 150 describes the properties of a workingmaterial in the free stream, i.e. at ambient pressure and specificvolume, and fourth station 165 approximately describes the properties ofa working material at the outlet or the exhaust of a thermodynamicapparatus, such as a turboshaft engine. The isobaric expansion 162 canthus occur in the wake, i.e. downstream, of an embodiment of theinvention. In other embodiments, the second cycle can be a closed cycle.

Both the first cycle and the second cycle produce a positive mechanicalwork output.

In some embodiments described by FIG. 8, the rate of heat removed fromthe working material in the second cycle during isobaric compression 160is substantially equal to the rate of heat added to the working materialin the first cycle during isobaric expansion 152. Note that the massflow rate of working material in the first cycle need not be equal tothe mass flow rate of working material in the second cycle. In someembodiments, the heat removed from the working material in the secondcycle is the same heat which is added to the working material in thefirst cycle. The heat transfer from the colder working material betweenstations 163 and 164 to the hotter working material between stations 155and 156 is facilitated by a heat transfer apparatus.

The working material in the first cycle need not be of the same type asthe working material of the second cycle. The working material of thefirst cycle can be air, while the working material of the second cyclecan be helium, for example.

In other embodiments, expansion 159 can be a compression instead, andcompression 161 can be an expansion instead, where the pressure at theequivalent second station 163 of the second cycle is lower than thepressure at the second station 155 of the first cycle. In suchembodiments, the first cycle produces a net mechanical work output,while the second cycle consumes work. In other words, the workingmaterial does work on the environment in the first cycle, and theenvironment does work on the working material in this particular secondcycle. The first cycle and the second cycle can be configured in amanner in which the combined power output of the first and second cyclesis positive.

FIG. 9 is a plot of material properties for one example embodimentduring one example method of operation. Some features of the cycle shownin FIG. 9 as well as some of the principles of operation of theassociated thermodynamic apparatuses share similarities with featuresand principles of operation described by the other figures, and willtherefore not be described in the same detail in the context of FIG. 9,and vice versa.

The horizontal x-axis 193 denotes the specific volume of the workingmaterial in question, and the vertical y-axis 194 denotes the pressureof the working material.

The depicted thermodynamic cycle comprises a first adiabatic expansion187 between first station 180 and second station 181, a first isobariccompression 188 to third station 182, a first adiabatic compression 189to fourth station 183, a first isobaric expansion 190 to fifth station184, a second adiabatic expansion 191 to sixth station 185, and a secondisobaric expansion 192 to a seventh station, which is equal to firststation 180.

In some embodiments, first station 180 describes the properties of aworking material in the free stream, e.g. air at ambient pressure andambient specific volume, and sixth station 185 approximately describesthe properties of a working material at the outlet or the exhaust of athermodynamic apparatus. The isobaric expansion 192 can thus occur inthe wake, i.e. downstream, of an embodiment of the invention. In otherembodiments, the first cycle can be a closed cycle.

The depicted thermodynamic cycle produces a net positive mechanical workoutput, i.e. the working a material does work on the environment.

In some embodiments described by FIG. 9, the rate of heat removed fromthe working material during isobaric compression 188 is substantiallyequal to the rate of heat added to the working material in the firstcycle during isobaric expansion 190. In some embodiments, the heatremoved from the working material during isobaric compression 188 is thesame heat which is added to the working material during isobaricexpansion 190. The heat transfer from the colder working materialbetween stations 181 and 182 to the hotter working material betweenstations 183 and 184 is facilitated by a heat transfer apparatus.

The working material can be a compressible gas such as air or carbondioxide. The thermodynamic apparatus performing the compression orexpansion processes can be a compressor or turbine of the axial flowtype, or of the centrifugal type, for example. These processes can alsobe carried out in a piston.

FIG. 10 is a plot of material properties for one example embodimentduring one example method of operation. Some features of the cycle shownin FIG. 10 as well as some of the principles of operation of theassociated thermodynamic apparatuses share similarities with featuresand principles of operation described by the other figures, and willtherefore not be described in the same detail in the context of FIG. 10,and vice versa.

The horizontal x-axis 218 denotes the specific volume of the workingmaterial in question, and the vertical y-axis 219 denotes the pressureof the working material.

The depicted thermodynamic cycle comprises a first adiabatic compression212 between first station 205 and second station 206, a first isobaricexpansion 213 to third station 207, a first adiabatic expansion 214 tofourth station 208, a first isobaric compression 215 to fifth station209, a second adiabatic compression 216 to sixth station 210, and asecond isobaric expansion 217 to a seventh station, which is equal tofirst station 205.

In some embodiments, first station 205 describes the properties of aworking material in the free stream, e.g. air at ambient pressure andambient specific volume, and sixth station 210 approximately describesthe properties of a working material at the outlet or the exhaust of athermodynamic apparatus. The isobaric expansion 217 can thus occur inthe wake, i.e. downstream, of an embodiment of the invention. In otherembodiments, the first cycle can be a closed cycle.

The depicted thermodynamic cycle produces a net positive mechanical workoutput, i.e. the working a material does work on the environment, i.e.the thermodynamic apparatus it interacts with.

In some embodiments described by FIG. 9, the rate of heat removed fromthe working material during isobaric compression 215 is substantiallyequal to the rate of heat added to the working material during isobaricexpansion 213. In some embodiments, the heat removed from the workingmaterial during isobaric compression 215 is the same heat which is addedto the working material during isobaric expansion 213. The heat transferfrom the colder working material between stations 208 and 209 to thehotter working material between stations 206 and 207 is facilitated by aheat transfer apparatus.

FIG. 11 is a schematic representation of a heat engine or heat pump.Some features of the cycles shown in FIG. 11 as well as some of theprinciples of operation of the associated thermodynamic apparatusesshare similarities with features and principles of operation describedby the other figures, such as FIG. 8 or FIG. 15 in particular, and willtherefore not be described in the same detail in the context of FIG. 11,and vice versa.

A first thermodynamic cycle comprises an inflow 230 of a workingmaterial into a expander 231, the outflow 232 of which is cooled by heattransfer apparatus 236, the outflow 237 of which flows into a compressor238 which is powered via work “WINTA” 234 by expander 231, and theoutflow 239 of which is released into the same reservoir which providesthe inflow 230. This reservoir can be the atmosphere, for example. Thesurplus work 233 of the thermodynamic cycle is available as “WOUTA”.

An expander, such as expander 231, can by any thermodynamic apparatuswhich can reduce the pressure of a working material. For example, anexpander can be a piston, an axial or centrifugal turbine, or a duct ornozzle. Typically, the working material will do mechanical work on theexpander. Typically, a portion of this mechanical work can be recoveredto do useful work, e.g. power an electric generator or produce thrust.

A second thermodynamic cycle comprises an inflow 241 of a workingmaterial into a compressor 242, which is powered via a work “WINTB” 244by expander 248, and the outflow 243 of which is heated by heat transferapparatus 236, the outflow 247 of which flows into a expander 248, theoutflow 249 of which is released into the same reservoir which providesthe inflow 241. This reservoir can be the atmosphere, for example. Thesurplus work 250 of the thermodynamic cycle is available as “WOUTB”.

The rate of heat flow “QINT” is flowing through heat transfer apparatus236.

The first thermodynamic cycle shown in FIG. 8 corresponds to the secondthermodynamic cycle shown in FIG. 11 for some embodiments. The secondthermodynamic cycle shown in FIG. 8 corresponds to the firstthermodynamic cycle shown in FIG. 11 for some embodiments.

FIG. 12 is a schematic representation of a heat pump or a heat engine.Some features of the cycle shown in FIG. 12 as well as some of theprinciples of operation of the associated thermodynamic apparatusesshare similarities with features and principles of operation describedby the other figures, such as FIG. 14 or FIG. 10 in particular, and willtherefore not be described in the same detail in the context of FIG. 12,and vice versa.

The depicted thermodynamic cycle comprises an inflow 260 of workingmaterial into a first compressor 261, which is powered via a shaft 263by expander 267, and the outflow 262 of which is heated by a heattransfer apparatus 265, the outflow 266 of which flows into a expander267, the outflow 268 of which is cooled by a conventional heat exchanger269, the outflow 270 of which flows into a second compressor 271, whichis powered via a shaft 275 by expander 267, and the outflow 272 of whichis released into the same reservoir which provides the inflow 260. Athermal fluid within a pipe apparatus 274 is circulated by a pump inorder to enhance the heat transfer from heat exchanger 269 to heattransfer apparatus 265. Heat flow “QINT” flows through heat transferapparatus 265. The surplus work of the thermodynamic cycle is available“WOUT” 273.

FIG. 13 is a schematic representation of a heat pump or a heat engine.Some features of the cycle shown in FIG. 13 as well as some of theprinciples of operation of the associated thermodynamic apparatusesshare similarities with features and principles of operation describedby the other figures, such as FIG. 9 in particular, and will thereforenot be described in the same detail in the context of FIG. 13, and viceversa.

The depicted thermodynamic cycle comprises an inflow 290 of workingmaterial into a first expander 291, the outflow 292 of which is cooledby a conventional heat exchanger 295, the outflow 296 of which flowsinto a compressor 297, which is powered via a shaft 293 by firstexpander 291 and/or via shaft 305 by second expander 301, and theoutflow 298 of which is heated by a heat transfer apparatus 299, theoutflow 300 of which flows into a second expander 301, the outflow 302of which is released into the same reservoir which provides the inflow290. A thermal fluid within a pipe apparatus 304 is circulated by a pumpin order to enhance the heat transfer from heat exchanger 295 to heattransfer apparatus 299. Heat flow “QINT” flows through heat transferapparatus 299. The surplus work of the thermodynamic cycle is available“WOUT” 303.

In other embodiments, the location of the exchanger can be reversed withthe location of the heat transfer apparatus. In other words, the heatexchanger can be located downstream of compressor 297 and upstream ofsecond expander 301, and the heat transfer apparatus can be locateddownstream of first expander 291 and upstream of compressor 297.

In general, the heat can be transported from outflow 292 to outflow 298via any number of heat exchangers and any type of heat transportmechanism, such as radiation, natural or forced convection, orconduction, as long as at least one suitably configured heat transferapparatus, such as the heat transfer apparatuses shown in FIG. 1, FIG.4, or FIG. 15, is located along the thermal path between outflow 292 andoutflow 298. The same applies to FIG. 11 and FIG. 12. In the exampleshown in FIG. 13, for instance, the heat is transferred from outflow 262via forced convection of a thermal fluid through a pipe apparatus 304,and subsequently via conduction into the heat transfer apparatus 299,from which the heat is delivered to outflow 298 via conduction,radiation.

FIG. 14 is a cross-sectional view of one embodiment of the invention.Some features of the cycle shown in FIG. 14 as well as some of theprinciples of operation of the associated thermodynamic apparatusesshare similarities with features and principles of operation describedby the other figures, such as FIG. 12 and FIG. 10 in particular, andwill therefore not be described in the same detail in the context ofFIG. 14, and vice versa.

Engine 320 shares features and principles of operation with aconventional turbojet or turboshaft engines. Engine 320 comprises a ductapparatus 321 and an inside apparatus 322.

Several components of engine 320 are substantially axially symmetricabout axis 369.

Bulk material 323 of engine 320 can comprise several different materialtypes. For example, bulk material 323 can comprise metals such astitanium or aluminum, ceramics, or composites, such as carbon fibercomposites or fiberglass.

Inside apparatus 322 comprises an optionally annular shaped channel 342between annular inlet 341 and annular outlet 343, and between outerinside surface 349 and interior inside surface 350. The outside surface348 of duct apparatus 321 is indicated.

A working material flows through channel 342 from inlet 341 to outlet343. The working material can be a compressible fluid. The fluid can bea gas such as air or carbon dioxide for example. Note that liquids suchas water are also compressible.

After passing through inlet 341, the working material flowing throughchannel 342 sequentially encounters a first compressor 324, a first heatexchanger 326, a turbine 332, a second heat exchanger 334, and a secondcompressor 340 before exiting through the outlet 343.

In this embodiment, the first compressor 324 and the second compressor340 can be described as axial flow compressors. Other embodiments cancomprise other types of compressors. The compressors can be centrifugalcompressors, for example.

In this embodiment, the turbine 332 is an axial flow turbine. Otherembodiments can comprise other types of turbines. The turbines can becentrifugal turbines, for example.

The compressors and turbine may comprise several rotor blades, such asrotor blade 346, and several stator blades, such as stator blade 347.The rotor blades of a rotor disc are arranged circumferentially aboutthe axis rotation, i.e. axis 369. The stator blades area also arrangedcircumferentially. A rotor disc and the downstream stator disc form astage. In the depicted embodiment, the turbine has 4 stages. In otherembodiments, the compressors and the turbine can have at least onestage. In other embodiments, the compressors and the turbine can have atleast one rotor disc, where each rotor disc has at least one rotorblade.

In the depicted embodiment, the individual compressor rotor blades ofthe first and second compressors and the individual turbine rotor bladesare connected to the same shaft. Engine 320 can therefore be describedas a single spool engine.

In other embodiments, the engine can be a multi-spool engine. In otherwords, there can be more than one drive shaft being driven by at leastone turbine rotor disc. For example, consider the following embodiment.The first two turbine rotor discs counted in a downstream direction canbe connected to a first drive shaft which is connected to the second andthird compressor rotor discs of the first compressor 324. The thirdturbine rotor disc can be connected to a second drive shaft which isconnected to the first compressor rotor disc of the first compressor324. The third turbine rotor disc can be connected to a third driveshaft, which can power an electric generator, the propeller apparatus ofa turboprop aircraft, or the fan of a turbofan aircraft, for instance.The fourth turbine rotor disc can be connected to a fourth drive shaft,which is connected to all of the compressor rotor discs of the secondcompressor 340.

First heat exchanger 326 is configured to transfer heat from a heattransfer apparatus 351 to the working material in channel 342 duringnominal operations. The location of heat exchanger 326 inside channel342, i.e. the portion of channel 342 located downstream of firstcompressor 324 and upstream of turbine 332 is denoted the heatingchamber. In this particular embodiment, this is accomplished via forcedconvection of a thermal fluid by a pump, such as pump 329, through apipe apparatus. The thermal fluid can be water, oil, molten salt, or afluid specially adapted for the application of transferring heat from afirst reservoir, such as the radially outward portion of the heattransfer apparatus 351, to a second reservoir, such as the workingmaterial in the heating chamber, via forced convection. In someembodiments, the thermal fluid can undergo a phase change throughout thepipe apparatus. The pipe apparatus and pump 329 facilitate the transportof said thermal fluid through the heat transfer apparatus 351 andthrough the working material in the heating chamber. In this particularembodiment, the portion of the pipe apparatus within channel 342 can bedescribed as a counter-current heat exchanger. In other embodiments, theheat exchanger can be a co-current heat exchanger, or a cross-flow heatexchanger, for example. The portion of the pipe apparatus which is incontact with the working material in channel 342 comprises severalsmaller pipes, such as pipe 327, in order to increase the contact areaand enhance the heat flow rate from the thermal fluid to the workingmaterial. The portion of the pipe apparatus of first heat exchanger 326which is enclosed by the annular, cylindrical heat transfer apparatus351 indicates the location where heat is transferred from the heattransfer apparatus 351 to the thermal fluid inside the pipe apparatus offirst heat exchanger 326. Once the heat has been transferred from theheat transfer apparatus 351 to the thermal fluid inside the pipeapparatus, the pipe apparatus transports the thermal fluid back to theheating chamber, where heat is transferred from the thermal fluid to theworking material.

Note that the thermal fluid heats the working material and transfersheat from the radially outward portion of the heat transfer apparatus351 during nominal operations. The term “thermal” is used only toindicate the transport of heat by the fluid, and should not beinterpreted to indicate the magnitude or direction of the change oftemperature of any thermal reservoirs associated with, or in thermalcontact with, the thermal fluid. The thermal fluid can also be describedas a cooling fluid, or a refrigerant. Since the channel 342 is annular,the heat exchanger 326 is axially symmetric about axis 369.

Second heat exchanger 334 is configured in a similar manner as firstheat exchanger 326, and vice versa. Second heat exchanger 334 isconfigured to transfer heat from the working material in channel 342 tothe radially inward portion, or the base, of heat transfer apparatus 351during nominal operations. The location of heat exchanger 334 insidechannel 342, i.e. the portion of channel 342 located downstream ofturbine 332 and upstream of second compressor 340 is denoted the coolingchamber. As before, this is accomplished via forced convection of athermal fluid by a pump, such as pump 337, through a pipe apparatus 336.Note that the thermal fluid in the second heat exchanger 334 need not beidentical to the thermal fluid in the first heat exchanger 326. The pipeapparatus 336 and pump 337 facilitate the transport of said thermalfluid through the heat transfer apparatus 351 and through the workingmaterial in the cooling chamber. In this particular embodiment, theportion of the pipe apparatus within channel 342 can be described as acounter-current heat exchanger. The portion of the pipe apparatus whichis in contact with the working material in channel 342 comprises severalsmaller pipes, such as pipe 335. The portion of the pipe apparatus 336which is enclosed by heat transfer apparatus 351 indicates the locationwhere heat from the thermal fluid inside pipe apparatus 336 istransferred to the heat transfer apparatus 351. Once the heat has beentransferred from the thermal fluid to the heat transfer apparatus 351,the pipe apparatus 336 transports the thermal fluid back to the pump andthe cooling chamber, where heat is transferred from the working materialto the thermal fluid.

Heat transfer apparatus 351 is configured to be able to transfer heatfrom a first thermal reservoir to a second thermal reservoir, where thetemperature of the first thermal reservoir is lower than the temperatureof the second thermal reservoir. During nominal operations, thetemperature of the first thermal reservoir of heat transfer apparatus351 is lower than the temperature of the second thermal reservoir. Thusthe first thermal reservoir can be denoted the cold reservoir, and thesecond thermal reservoir can be denoted the hot reservoir. In engine320, the cold reservoir comprises the working material in the coolingchamber, and the hot reservoir comprises the working material in theheating chamber.

The temporal variation of the thermodynamic properties of the workingmaterial flowing through channel 342 is similar to the variationdepicted in FIG. 10, and the thermodynamic system is also described bythe schematic diagram shown in FIG. 12.

Following a compression, the working material is heated, expanded,cooled, and compressed once more before passing through outlet 342. Inthe wake of engine 320, the working material having passed throughchannel 342 is heated by the surrounding working material and returnedto substantially the original, free stream thermodynamic properties.This thermodynamic cycle can be described as an open cycle, since work,matter and heat are exchanged with the environment, i.e. the regionoutside of channel 342. Other embodiments can fully enclose a workingmaterial, resulting in a closed thermodynamic cycle. Some suchembodiments can comprise an apparatus similar to engine 320, in additionto a channel section which connects outlet 343 with inlet 341, wheresaid channel section comprises a third heat exchanger which isconfigured to transfer heat from the environment outside of the closedchannel into the closed channel. Depending on the temperature of theoutside environment, the third heat exchanger can be configured totransfer heat from a cold reservoir outside to a hot reservoir insidethe closed channel, or from a hot reservoir outside to a cold reservoirinside the closed channel, as long as heat is transferred from theoutside environment into the closed channel by the third heat exchanger.

Note that the aforementioned embodiments are configured to convertthermal energy into mechanical work. In FIGS. 8-10, the amount of workis determined by the areas enclosed by the closed curves, where the signof the work done by the working material is positive for a clockwisecycle and negative for an anti-clockwise cycle. The thermal energy isdetermined by the net thermal energy absorbed from the externalreservoir. This is the heat absorbed during the isobaric expansion 192in FIG. 9, or the isobaric expansion 217 in FIG. 10, or the heatabsorbed during the isobaric expansion 162 from which the heat releasedduring the isobaric compression 154 is subtracted. When neglectingfriction, the net heat absorbed by the working material during onecycle, i.e. the heat absorbed during isobaric expansion 192, forexample, is equal to the net mechanical work done by the workingmaterial. In this idealized scenario, from the point of view of theexternal reservoir, i.e. the reservoir providing the thermal energyduring isobaric expansion 192, for example, the thermal energy isconverted into mechanical work. Note that the thermodynamic system neednot be closed. In other words, the mass can be exchanged with anexternal reservoir, as discussed in the context of FIGS. 11-15. For someembodiments, the working material is identical to and sourced from thematerial found in the aforementioned external reservoir.

In other embodiments, mechanical work can be converted into thermalenergy. In such embodiments, the heat flow direction between the workingmaterial and the heat exchangers can be reversed compared to theaforementioned embodiments. The direction of the cycles shown in FIGS.8-10 can be reversed, i.e. a compression can be replaced by anexpansion, and vice versa, resulting in a sign change of the work doneby the working material and the thermal energy absorbed by the workingmaterial. In other words, work is now done on the working material, andthermal energy is released by the working material into an externalreservoir. The term “engine” used herein refers to both a heat engineand a heat pump.

The rate of heat extracted from the working material in the coolingchamber is substantially equal to the rate of heat added to the workingmaterial in the heating chamber in the depicted embodiment.

In other embodiments, there can be alternative or additional heatsources or heat sinks which can contribute to heat transferred to theworking material in the heating chamber, or contribute to heat removedfrom the working material in the cooling chamber. For example, when anengine similar to engine 320 is employed to power an aircraft or a ship,a portion of the wetted surface area of the fuselage or the hull of theship can be configured to extract heat from the surrounding fluid. Thus,a portion of the outside environment or a portion of the fluid notflowing through channel 342 can be cooled, and act as a heat source tothe working material in the heating chamber in a similar manner in whichthe working material in the cooling chamber acts as a heat source to theworking material in the heating chamber. Alternatively or concurrently,a portion of the fluid in contact with the fuselage or hull of the shipcan be configured to transfer heat into the surrounding fluid. Thus, aportion of the outside environment or a portion of the fluid not flowingthrough channel 342 can be heated, and act as a heat sink to the workingmaterial in the cooling chamber in a similar manner in which the workingmaterial in the heating chamber acts as a heat sink to the workingmaterial in the cooling chamber.

The principles of the invention can also be applied to other types ofthermodynamic apparatuses, such as turboshaft engines, turbopropengines, turbofan engines, piston engines, refrigerators, orair-conditioning systems, for example.

In another embodiment, the first and second compressors of engine 320are replaced by a first and second turbine through which the workingmaterial is expanded, and the turbine of engine 320 is replaced by acompressor. The temporal variation of the thermodynamic properties ofthe working material flowing through such an embodiment is similar tothe variation depicted in FIG. 9, and the thermodynamic system is alsodescribed by the schematic diagram shown in FIG. 13.

In engine 320, the compressors and the turbine change the properties ofthe working material adiabatically. In other embodiments, there can bean exchange of heat with the environment during the compression orexpansion of the working material. In some embodiments, the firstcompression, second compression, or expansion can be isothermal. Theheat transfer from the working material during an isothermal compressionor to the working material during an isothermal expansion can bearranged in a similar manner as the heat transfer from the coolingchamber to the heating chamber in engine 320, or from the outsideenvironment, as mentioned.

In other embodiments, the first engine 390 can be replaced by aconventional heat exchanger which is configured to extract heat from aworking material, such as the fluid surrounding the hull of a ship orthe skin of an aircraft, such as the skin of the wing, fuselage orempennage, and transfer it to the heat transfer apparatus 472, which inturn is configured to transfer the heat to at least one engine, such asengine 431.

FIG. 15 is a cross-sectional view of three components of anotherembodiment of a heating or refrigeration system. Some features of theapparatus shown in FIG. 15, as well as some of the principles ofoperation of the apparatus share similarities with the apparatus shownin the other figures, such as FIG. 8 and FIG. 11 in particular, and willtherefore not be described in the same detail in the context of FIG. 15,and vice versa.

The first component is a first engine 390, the second component is aheat transfer apparatus 472, and the third component is a second engine431.

First engine 390 comprises a duct apparatus 391 and an inside apparatus392. Several components of engine 390 are substantially axiallysymmetric about axis 422.

Inside apparatus 392 comprises an optionally annular shaped channel 395between annular inlet 394 and annular outlet 403, and between the outerinside surface and the interior inside surface.

A working material flows through channel 395 from inlet 394 to outlet403. The working material can be a compressible fluid. As before, thefluid can be a gas such as air, for example.

After passing through inlet 394, the working material flowing throughchannel 395 sequentially encounters a turbine 396, a heat exchanger 398,and a compressor 402 before exiting through the outlet 403.

In this embodiment, the turbine 396 and the compressor 402 can bedescribed as an axial flow turbine and compressor. Other embodiments cancomprise other types of turbomachinery, such as centrifugal compressorsor turbines, for example. The principles of the invention can also beapplied to embodiments comprising pistons, such as those found in areciprocating engine or pump.

Heat exchanger 398 is configured to transfer heat from the workingmaterial in channel 395 to heat transfer apparatus 472 during nominaloperations. The location of heat exchanger 398 inside channel 395, i.e.the portion of channel 395 located upstream of compressor 402 anddownstream of turbine 396 is denoted the cooling chamber. In thisparticular embodiment, this is accomplished via forced convection of athermal fluid by a pump, such as pump 487, through pipe apparatus 486.The thermal fluid can be water, or oil, or a fluid specially adapted forsaid forced convection. The pipe apparatus and pump 487 facilitate thetransport of said thermal fluid through the heat transfer apparatus 398.In this particular embodiment, the portion of the pipe apparatus 486within channel 395 can be described as a counter-current heat exchanger.The portion of the pipe apparatus which is in contact with the workingmaterial in channel 395 comprises several smaller pipes, such as pipe399, in order to increase the contact area and enhance the heat flowrate from the working material to the thermal fluid.

In other embodiments, the thermal fluid can transport heat through theheat exchanger 398 via natural convection. In other embodiments, theheat exchanger 398 can transport heat from the cooling chamber to theheat transfer apparatus 472 via thermal conduction. For example, thepiping apparatus 486 can consist of a solid material such as copper orsilver, or the piping apparatus can comprise a different suitablematerial, such as a material with a high coefficient of thermalconductivity. A wide variety of other methods for exchanging heat areavailable.

Second engine 431 comprises a duct apparatus 432 and an inside apparatus433. Several components of engine 431 are substantially axiallysymmetric about axis 463.

Inside apparatus 433 comprises an annular channel 436 between annularinlet 435 and annular outlet 444, and between the outer inside surfaceand the interior inside surface.

A working material flows through channel 436 from inlet 435 to outlet444. The working material can be a compressible fluid. As before, thefluid can be a gas such as air, for example.

After passing through inlet 435, the working material flowing throughchannel 436 sequentially encounters a compressor 437, a heat exchanger439, and a turbine 443 before exiting through the outlet 444.

In this embodiment, the turbine 443 and the compressor 437 can bedescribed as an axial flow turbine and compressor.

Heat exchanger 439 is configured to transfer heat from heat transferapparatus 472 to the working material in channel 436 during nominaloperations. The location of heat exchanger 439 inside channel 436, i.e.the portion of channel 436 located downstream of compressor 437 andupstream of turbine 443 is denoted the heating chamber. In thisparticular embodiment, this is accomplished via forced convection of athermal fluid by a pump, such as pump 490, through pipe apparatus 489.The thermal fluid can be water, or oil, or a fluid specially adapted forsaid forced convection. The pipe apparatus and pump 490 facilitate thetransport of said thermal fluid through the heat transfer apparatus 439.In this particular embodiment, the portion of the pipe apparatus 489within channel 436 can be described as a counter-current heat exchanger.The portion of the pipe apparatus which is in contact with the workingmaterial in channel 436 comprises several smaller pipes, such as pipe440, in order to increase the contact area and enhance the heat flowrate from the thermal fluid to the working material.

The working material flowing through channel 436 during nominaloperations is the same working material flowing through channel 395 inthe depicted embodiment. For example, the working material can be airfor both first engine 390 and second engine 431. In other embodiments,the working material flowing through first engine 390 and second engine431 need not be identical. Other embodiments can comprise at least oneengine, such as engine 390 or engine 431. Embodiments comprising asingle engine can comprise a conventional heat exchanger. For example,the first engine 390 can be replaced by a conventional heat exchangerwhich is configured to exchange heat between the heat transfer apparatus472 and a thermal reservoir. The medium within the thermal reservoir canbe air surrounding an aircraft or the water surrounding a ship, forexample. In some such embodiments the heat transfer apparatus 472 can beconfigured to transfer heat from said thermal reservoir into the heatingchamber of engine 431. In some such embodiments, the working materialflowing through engine 431 can be a gas such as air, and the workingmaterial flowing through, or interacting with, or exchanging heat with,the conventional heat exchanger can be a gas, a liquid, or any otherthermal reservoir. In other embodiments, the second engine 431 can bereplaced by a conventional heat exchanger, and the heat transferapparatus 472 can be configured to transfer heat from the coolingchamber of engine 390 into a thermal reservoir in thermal contact withsaid heat exchanger.

In other embodiments, heat can also be transferred to the workingmaterial within heating chamber of engine 431 by external heat or mattersources, such as the heat provided by the chemical reactions, such as achemical reaction between fuel and portions of the working material.

Heat transfer apparatus 472 is configured to be able to transfer heatfrom a first thermal reservoir to a second thermal reservoir, where thetemperature of the first thermal reservoir is lower than the temperatureof the second thermal reservoir. During nominal operations, thetemperature of the first thermal reservoir of heat transfer apparatus472 is lower than the temperature of the second thermal reservoir. Thusthe first thermal reservoir can be denoted the cold reservoir, and thesecond thermal reservoir can be denoted the hot reservoir. For theembodiment depicted in FIG. 15, the cold reservoir comprises the workingmaterial in the cooling chamber in engine 390, and the hot reservoircomprises the working material in the heating chamber in engine 431.

Heat transfer apparatus 472 comprises a casing apparatus 473 and anannular rotating apparatus 475, which is configured to rotate relativeto casing apparatus 473 during nominal operations about axis 495. Casingapparatus 473 is cylindrical in shape, with the central axis of symmetrybeing coincident with axis 495 in this embodiment. In other words, thecross-section of casing apparatus 473 is circular when viewed along axis495. Casing apparatus 473 also comprises a hollow central shaft 484.Rotating apparatus 475 is also axially symmetric about axis 495.Rotating apparatus 475 encloses a central volume 496, which is annularabout axis 495 and rectangular in cross-section when viewed along anaxis perpendicular to axis 495, as shown.

Central volume 496 comprises a material which, when compressedadiabatically, can experience an increase in temperature. In thedepicted embodiment, central volume 496 comprises a compressible gassuch as helium, hydrogen, or air. It can be advantageous to select acentral material with a large coefficient of thermal conductivity. Thiscan increase the rate of heat flow from the cooling chamber to theheating chamber for a given apparatus operating condition, and thusincrease the net power output, ceteris paribus. A small specific heatcapacity at constant pressure can help reduce the mass of the heattransfer apparatus 472 for some embodiments. For instance, a smallerspecific heat capacity can lead to a smaller angular rate of rotation ofrotating apparatus 475, reducing the size of load carrying members. Insome embodiments, central volume 496 can comprise a solid such as ametal or a liquid such as water. Note that the material in centralvolume 496, denoted the central material, can be of the same type as theworking material flowing through channel 436 or channel 395.

In order to minimize viscous friction due to the relative motion of thecasing apparatus and the rotating apparatus 475, the separation volume497 between the rotating apparatus 475 and the casing apparatus 473 isevacuated in the depicted embodiment. In other embodiments, theseparation volume 497 can comprise a fluid. For example, the fluid canbe helium or lubricating oil. Such a fluid can increase the pressurewithin separation volume 497 and reduce the mass of casing apparatus473, without increasing the energy losses associated with the relativemotion of casing apparatus 473 and rotating apparatus 475 by anunnecessarily large amount.

The geometry of rotating apparatus 475 can also be adapted to the largecentripetal loads within the walls of rotating apparatus 475 in a mannerwhich reduces the mass of the rotating apparatus 475 for a given heatflow rate or radius. For example, the cross-section of annular rotatingapparatus 475 can be a teardrop shape, or share similarities to ateardrop shape, when viewed along an axis perpendicular to rotation axis497, where the long axis of the teardrop is perpendicular to therotation axis 497, and where the nominally rounded, blunt end of theteardrop is located in a radially outward direction compared to thenominally sharper end. In such embodiments, the casing apparatus canhave a spherical shape. In other such embodiments, the casing apparatuscan have a cylindrical shape, where the central portion of the outsidesurface is parallel to axis 495, and the end portions are convex, i.e.rounded outwards, or concave, i.e. rounded inwards. A wide variety ofother geometries of the casing apparatuses and of the rotatingapparatuses are available.

The preferred path of the heat flow from pipe apparatus 494 to pipeapparatus 489 is from to interior inside surface 477 to interior outsidesurface 476 via the adjoining portion of the separation volume, throughthe interior wall of rotating apparatus 475 which is parallel to axis495, through central volume 496, through the exterior wall of rotatingapparatus 475 which is parallel to axis 495, from exterior insidesurface 480 to exterior outside surface 479 via the adjoining portion ofthe separation volume, as indicated by the arrows perpendicular to axis495.

The thermal fluid is transported through pipe apparatus 486 to aninterior inside surface 477 via several smaller pipes, such as pipe 494.Heat can be delivered from a pipe apparatus to the interior insidesurface 477 via thermal conduction. Interior inside surface 477 isconfigured to transfer heat to the interior outside surface 476 viathermal radiation through the evacuated separation volume 497. In otherembodiments, at least a portion of said heat transfer can compriseconduction through a material, such as a gas or a liquid, containedwithin separation volume 497. In some embodiments, at least a portion ofsaid heat transfer can comprise thermal conduction through thecomponents of a roller bearing between and inside surface and anopposing outside surface.

Interior inside surface 477 is cylindrical in shape, and encloses aportion of central shaft 484. Interior outside surface 476 is alsocylindrical in shape and connected to the cylindrical interior surfaceof rotating apparatus 475. The distance of separation between interiorinside surface 477 and interior outside surface 476 is as small aspossible in order to maximize the rate of heat flow between saidsurfaces. This also applies to the distance of separation betweenexterior inside surface 480 and exterior outside surface 479. Theaforementioned inside or outside surfaces can comprise metal, such ascopper or aluminium.

In some embodiments, the inside surfaces and the outside surfacescomprise radial protrusions, where, in general, a protrusion of theinside surface is located between two protrusions of the outsidesurface. In this manner, the surface area of the interface between aninside surface and an outside surface can be artificially increased. Alarger interface area can increase the rate of heat transfer between theinside surface and the outside surface for a given averagecircumferential footprint of the inside and outside surfaces. Forexample, a protrusion can be an annular, flat, metal disc, where theplane of the disc is perpendicular to axis 495. The metal disc can berigidly connected to the associated surface, such as an inside surfaceor an outside surface. A protrusion of an inside surface can be locatedbetween two protrusions of an outside surface, such that the protrusionsof the inside surface and the outside surface interleave withouttouching. In order to maximize the interface area between an insidesurface and an outside surface, the protrusions, or discs, or fins, canbe configured to be thin, and the gap between protrusions can beminimized. The protrusions can be electrostatically charged such thatthe protrusions of an inside surface and the protrusions of an outsidesurface electrostatically repel. In this manner, thin and flexibleprotrusions of an inside surface can be placed in close proximity to thethin and flexible protrusions of an outside surface without theprotrusions coming into contact, or touching. Contact would result infrictional losses due to the relative motion of the rotating apparatus475 and the casing apparatus 473. In other embodiments, the repulsiveforces between adjacent protrusions can be provided by magnetic fields.Repelling permanent magnets can be embedded in the protrusions, forexample. Alternatively, electric conductors can be embedded within theprotrusions, such that electric current can be made to flow in theopposite circumferential direction in adjacent conductors of adjacentprotrusions, resulting in a repulsive magnetic force. A wide variety ofother methods are available to ensure separation between adjacentprotrusions.

A bearing assembly prevents the rotating apparatus 475 from contactingthe casing apparatus 473. The bearing assembly is not shown in FIG. 15.The bearing assembly can be located on exterior inside and outsidesurfaces, for example. Alternatively the bearing assembly can be locatedon the interior inside and outside surfaces.

The heat transferred to the interior outside surface 476 is conductedthrough the interior wall of the rotating apparatus 475 and into thecentral material in central volume 496. The material of the inside wallcan comprise material with a high coefficient of thermal conductivity,such as copper or silver. In other embodiments, the heat can betransferred through the interior wall by forced convection through aseparate pipe apparatus by a pump, such that heat can be transferredfrom interior outside surface 476 to the central material. In otherembodiments, the interior wall of central volume 496, i.e. the wallclosest to axis 495, can also comprise protrusions, pins, fins, orplates in order to increase the surface area of the interior wall. Thiscan increase the heat flow rate from the interior wall into the centralmaterial compared to a two dimensional cylindrical inside wall surfaceof central volume 496 shown in FIG. 15 for simplicity. The outside wallof central volume 496, i.e. the wall facing in a radially inwarddirection, can also be endowed with protrusions in order to increase thesurface area.

Baffles within central volume 496 ensure the fluid within central volume496 rotates together with the walls of rotating apparatus 475. This isparticularly relevant during acceleration or deceleration of the rate ofrotation of the walls of rotating apparatus 475. Each baffle is planarin this embodiment, where each plane is parallel to axis 495 andparallel to a vector perpendicular to axis 495. Other embodiments do notcomprise baffles as described. For example, the material within centralvolume 496 can be a solid, or the viscous friction between the fluid andthe walls of central volume 496 can be used to accelerate or deceleratethe rate of rotation of the fluid within central volume 496 such that,in the steady state, the angular rate of rotation of the fluid matchesthe angular rate of rotation of the solid walls of the rotatingapparatus 475. In other embodiments, the central material can beconfined by electrostatic or magnetic fields as opposed to the solidwalls depicted in FIG. 15.

Due to the rotation of the central material, there is a pressuregradient within central material, where the pressure increases in aradially outwards direction, as discussed in the context of FIG. 4 andFIG. 1. In the depicted embodiment, the walls of rotating apparatus 475are insulated. For simplicity, one can consider the walls to be perfectthermal insulators. In this simplified model, the compression of thecentral material in the radially outward direction relative to axis 495can be considered to be adiabatic. As a result, the temperature of thecentral material increases in a radially outward direction, resulting ina larger temperature at the outside wall of central volume 496 than atthe inside wall of the same. The difference of the temperature at theoutside wall and the inside wall of central volume 496 is denoted theinternal temperature difference. The magnitude of the internaltemperature difference is a function of the material properties of thecentral material, such as the specific heat capacity at constantpressure, as well as the angular rate of rotation of the rotatingapparatus 475, as well as the geometry of the rotating apparatus 475, inparticular the radius of the inside wall and the radius of the outsidewall, amongst other parameters. When the internal temperature differenceis sufficiently large, heat can be made to flow from the cooling chamberof engine 390 to the heating chamber of engine 431. When assuming, forthe sake of example, perfect thermal conductivity between the insidewall of central volume 496 and the cooling chamber of engine 390 as wellas between the outside wall of central volume 496 and the heatingchamber of engine 431, as well as instantaneous heat transfer betweenthe pipe apparatuses and the working materials, the internal temperaturedifference should be larger than the temperature difference of theworking material entering the heating chamber and the working materialentering the cooling chamber. In this case, heat can be made to flowthrough the central volume 496 in the radially outward direction viathermal conduction from a cold reservoir to a hot reservoir.

Note that, in some embodiments, heat can be lost by conduction,convection, or radiation through separation volume 497. These heatlosses can be mitigated by separation volume 497 comprising a materialwith a low thermal conductivity, by minimizing the size of separationvolume 497, or by placing insulating material around the preferred pathof the heat flow from pipe apparatus 494 to pipe apparatus 489, forexample.

Similarly to the transfer of heat from interior inside surface 477 tothe inside wall of central volume 496, heat can be transferred from theexterior inside surface 480 to the exterior outside surface 479. Atexterior outside surface 479, the heat is transferred to a thermal fluidinside pipe apparatus 489 via thermal conduction. The thermal fluidinside pipe apparatus 489 is pumped by pump 490 to heat exchanger 439 inthe heating chamber of engine 431, where the heat is transferred to theworking material inside channel 436.

In some embodiments, the heat transfer apparatus 472 can be locatedwithin an engine, such as engine 431. For example, axis 495 can becoincident with axis 463, and heat transfer apparatus 472 can be locatedwithin the volume enclosed by channel 436. In other embodiments, anengine can be located within heat transfer apparatus 472. For example, aportion of engine 390 can be located within hollow central shaft 484,with axis 422 being coincident with axis 495.

The temporal variation of the thermodynamic properties of the workingmaterial flowing through channel 395 is similar to the variationdepicted in the second cycle in FIG. 8. The temporal variation of thethermodynamic properties of the working material flowing through channel436 is similar to the variation depicted in the first cycle in FIG. 8.The thermodynamic system in FIG. 15 is also described by the schematicdiagram shown in FIG. 11.

Both the first engine 390 and the second engine 431 produce a positivemechanical work output in this embodiment.

In some embodiments, axis 463, axis 495, and axis 422 are substantiallycoincident. For example, a portion of engine 390 can be located withinhollow central shaft 484, and heat transfer apparatus 472 can beenclosed by channel 436 of engine 431. In other embodiments the ordercan be reversed. Heat transfer apparatus 472 can enclose engine 431,both of which are enclosed by channel 395 of engine 390.

In other embodiments, engine 390 can be configured in a similar manneras engine 431. In other words, after passing through inlet 394, theworking material flowing through channel 395 sequentially encounters acompressor, a cooling chamber containing heat exchanger 398, and aturbine before exiting through outlet 403. In this case, the temperatureof the working material exiting the compressor is lower than thetemperature of the working material exiting compressor 437 in engine431. As before, heat transfer apparatus 472 is configured to transferheat from the working material in the cooling chamber of engine 390 tothe working material in the heating chamber of engine 431. Note thatengine 390 does work on the working material, while the working materialdoes work on engine 431. Combined, engine 390 and engine 431 can beconfigured to produce a net positive mechanical work output.

Note that, while the heat flow rate flowing out of the cooling chamberis substantially equal to the heat flow rate into the heating chamber,the mass flow rate of working material through engine 390 need not beequal to the mass flow rate through engine 431. Therefore the amount ofheat per unit mass removed from the working material in engine 390 neednot be equal to the amount of heat per unit mass added to the workingmaterial in engine 431. This allows for more flexibility in theoptimization of the design of engine 431 and 390 for a particularapplication. For example, the mass flow rate of working material throughengine 390 can be larger than the mass flow rate of working materialthrough engine 431. By increasing the mass flow rate through engine 390,the minimum temperature of the working material in the cooling chambercan be increased. This can increase the temperature at the inside wallof central volume 496, which can increase the average coefficient ofthermal conductivity of the central material, which can increase theheat flow rate from the cooling chamber to the heating chamber, whichcan increase the net positive power output of the combined apparatus.

In some embodiments, a substantial portion of the working materialexiting engine 431 through outlet 444 also enters engine 390 throughinlet 394. In some such embodiments, the working material having flownthrough engine 431 can be a small fraction of the total flow rate ofworking material entering engine 390. In other words, ambient workingmaterial, such as ambient air, is ingested into engine 390 together withworking material from the exhaust of engine 431. This can increase theaverage temperature of the working material entering engine 390, whichcan increase the temperature of the working material at the coolingchamber, which can increase the net power output of the combinedapparatus, as mentioned.

In other embodiments, heat transfer apparatus 472 can be configured in adifferent manner. In FIG. 15, the inertial loads on the central materialcan be considered to be a body force per unit mass which acts onelements of the central material in a radially outwards direction. Theinertial loads arise from the circular motion of the molecules of thecentral material rotating with rotating apparatus 475. This inertialload is also referred to as a centrifugal force, which is an apparentforce. As mentioned, a wide variety of other methods and apparatuses areavailable for generating a body force per unit mass within a centralmaterial.

FIG. 16 is a cross-sectional view of one exemplary embodiment 520 of aheat transfer apparatus. Some features of the embodiment shown in FIG.16 as well as some of the principles of operation of the embodimentshare similarities with features and principles of operation describedby the other figures, and will therefore not be described in the samedetail in the context of FIG. 16, and vice versa.

FIG. 16 shows a reservoir 521 comprising a thermal material 522. In thisparticular example, the thermal material 522 is a gas, where theindividual molecules or atoms can be electrically polarized by anapplied electric field. The gas can be air, nitrogen, helium, or argon,for example. In other embodiments, thermal material 522 can be a liquid,or a solid. The thermal material can also comprise permanently polarizedmolecules, as is the case for water.

An electrically and thermally insulating material 523 encompassesreservoir 521. Reservoir 521 is cylindrical in shape in this embodiment.In other embodiments, reservoir 521 can be rectangular or annular inshape, for example. Reservoir 521 can take any shape in general.

A first heat exchanger 526 is located in the proximity of a first point524 in reservoir 521. In this particular embodiment, first heatexchanger 526 comprises several fins, such as fin 530, which can bedescribed as a planar metal plate. A pipe 527 comprising a thermal fluidis rigidly attached to the fins, allowing heat to be conducted from thethermal material 522 to the fins, and from the fins into the thermalfluid within pipe 527, and vice versa. The thermal fluid is pumpedthrough the pipe by a pump, which is not shown. The pipe can thustransfer heat to heat exchanger 526, or deliver heat from heat exchanger526. In other embodiments, heat exchanger 526 can be configureddifferently. For example, heat exchanger 526 can employ conduction,radiation, or natural convection, as opposed to the aforementionedforced convection of the thermal fluid through pipe 527, to exchangeheat between first point 524 in reservoir 521 with another reservoir,which is also not shown.

A second heat exchanger 531 is located in the proximity of a secondpoint 525 in reservoir 521. The second heat exchanger 531 is configuredin a similar manner as first heat exchanger 526. In other embodiments,the second heat exchanger 531 can be configured in a different mannercompared to first heat exchanger 526. The second heat exchanger 531comprises plates or fins, such as fin 535, and pipe 532.

Heat transfer apparatus 520 comprises a body force generating apparatusconfigured to generate a body force per unit mass with a substantialcomponent in the vertically downwards direction, towards the bottom ofthe page, where the body force per unit mass is acting on the thermalmaterial 522 within reservoir 521.

The body force generating apparatus comprises several collections ofcharge, such as a first positive collection of charge 539, a secondpositive collection of charge 540, a third positive collection of charge541, and a negative collection of charge 542. These collections ofcharge can be contained within electrical conductors, such as a metalsuch as copper. A voltage difference applied between conductors, such asconductor 541 and conductor 542 will result in an accumulation of chargewithin both conductors. In the depicted embodiment, the net chargecontained within the body force generating apparatus is zero. Electricalconductors 541, 540, and 539 are annular in shape and encompass thecylindrical reservoir 521. Electrical conductor 542 is cylindrical inshape. The amount of charge contained within each collection of chargerelative to other collections of charge can be regulated by regulatingthe voltage associated with said collection of charge relative to othercollections of charge. A wide variety of other configurations ofcollections of charge can achieve the same effect as the depictedconfiguration. For example, collections of charge can be located withinreservoir 521.

As a result of the electric field within reservoir 521, the thermalmaterial 522 is electrically polarized. As a result of the collectionsof charge, the component of the electrical field along the longitudinalaxis of the page increases in the direction towards the bottom of thepage. Hence, the individual molecules of thermal material 522 experiencea body force per unit mass towards the bottom of the page. Inequilibrium, the pressure, density and temperature of the thermalmaterial 522 increase towards the bottom of the page. The temperature atsecond point 525 is therefore larger than the temperature at first point524. The pressure and the electric field applied to the thermal material522 are contained by the insulating material 523 in this particularembodiment.

Depending on the external temperature applied to first heat exchanger526 and second heat exchanger 531, heat can be made to flow through thethermal material 522 from first heat exchanger 526 to second heatexchanger 531, or vice versa. For example, if the external temperaturesof the first heat exchanger 526 and second heat exchanger 531 areidentical, heat will flow from the first exterior reservoir thermallyconnected to the first heat exchanger 526 through the first heatexchanger 526 to first point 524 and through the thermal material 522 tosecond point 525 and through second heat exchanger 531 to the secondexternal reservoir thermally connected to the second heat exchanger 531.This is due to the artificially created temperature difference betweenthe first point 524 and the second point 525 by the body forcegenerating apparatus, where the temperature difference is preserved bythe insulating material 523. The higher temperature at second point 525makes the first exterior reservoir appear to be hotter to the secondexterior reservoir. Thus the heat transfer apparatus 520 can be employedto transfer heat from a first exterior reservoir to a hotter secondexterior reservoir, provided the temperature difference between thefirst and second exterior reservoirs is smaller in magnitude than thetemperature difference between the first point 524 and the second point525 for the given operating condition.

When the temperature of the first exterior reservoir is greater than thetemperature of the second exterior reservoir, the rate of heat transferthrough the heat transfer apparatus configured in accordance with theinvention can be greater than an equivalent heat exchanger of the priorart. An equivalent heat exchanger of the prior art can be an infinitelythin contact surface between the first reservoir and the secondreservoir. The rate of heat transfer through the heat transfer apparatusis a function of the thermal conductivity, as well as the temperaturegradient. The finite length of the heat transfer apparatus will reducethe temperature gradient by increasing the length over which thedifference in temperature is measured compared to the theoreticalequivalent heat exchanger and associated thermal boundary layer. Thebuilt-in temperature difference of the heat transfer apparatus, i.e. thetemperature difference between a first point and a second point inequilibrium at zero heat flow, can offset this increase in length forsome embodiments and some configurations, however, resulting in a largertemperature gradient and a larger rate of heat transfer from a hotreservoir to a cold reservoir.

FIG. 17 is a cross-sectional view of one exemplary embodiment 570 of aheat transfer apparatus. Some features of the embodiment shown in FIG.17 as well as some of the principles of operation of the embodimentshare similarities with features and principles of operation describedby the other figures, and will therefore not be described in the samedetail in the context of FIG. 17, and vice versa.

FIG. 17 shows a reservoir 571 comprising a thermal material 572. In thisparticular example, the thermal material 572 is a gas, where theindividual molecules or atoms are positively or negatively charged. Inother embodiments, thermal material 572 can be a liquid, or a solid. Inother embodiments, thermal material 572 can comprise other types ofmobile charges, such as free moving electrons.

An electrically and thermally insulating material 573 encompassesreservoir 571. Reservoir 571 is cylindrical in shape in this embodiment.In other embodiments, reservoir 571 can be rectangular or annular inshape, for example. Reservoir 571 can take any shape in general.

A first heat exchanger 576 is located in the proximity of a first point574 in reservoir 571 and comprises several fins and pipe 577. A secondheat exchanger 581 is located in the proximity of a second point 575 inreservoir 571 and comprises several fins and pipe 582. These heatexchangers are configured in a similar manner as the heat exchangersshown in FIG. 16.

Heat transfer apparatus 570 comprises a body force generating apparatusconfigured to generate a body force per unit mass with a substantialcomponent along the long axis of the page, where the body force per unitmass is acting on the thermal material 572 within reservoir 571.

The body force generating apparatus comprises several collections ofcharge, such as a positive first collection of charge 589, a negativesecond collection of charge 590. A wide variety of other configurationsof a body force per unit mass generating apparatuses can be devised andemployed to produce an electrical potential energy difference forelements of the thermal material 572 between the first point 574 and thesecond point 575.

The electrical potential energy difference results in a temperaturedifference between the first point 574 and the second point 575 duringthermal equilibrium, i.e. zero heat flow between the first point 574 andthe second point 575. For example, when the thermal material comprisespositively charged ions, the ions will experience a body force per unitmass directed towards the bottom of the page within reservoir 571. Asdescribed in the context of FIG. 16, this results in a largertemperature at second point 575 compared to the first point 574. Thus,embodiment 570 can be operated as a heat transfer apparatus in the samemanner as embodiment 520 and other heat transfer apparatuses mentionedherein.

By reversing the polarity of the charge contained within the collectionsof charge, the direction of the body force within thermal material 572can be reversed. This can be used to control the direction of heat flowthrough the heat transfer apparatus. For example, this can be used tochange the mode of operation of the heat transfer apparatus 570 from themode corresponding to an artificial heat source to the modecorresponding to an artificial heat sink.

By regulating the magnitude of the potential difference applied to thefirst collection of charge 589 relative to the second collection ofcharge 590, the magnitude of the body force per unit mass within thereservoir 571 can be controlled. In this manner, the magnitude of thetemperature difference between the first point 574 and the second point575 can be controlled. This allows the rate of heat flow through thethermal material 571 and through the heat transfer apparatus 570 to becontrolled. Other methods for controlling the heat flow through heattransfer apparatus 570 are also available. For example, the mass flowrate of the thermal fluid through pipe 582 can be modified.

FIG. 18 is a cross-sectional view of one exemplary embodiment 610 of aheat transfer apparatus. Some features of the embodiment shown in FIG.18 as well as some of the principles of operation of the embodimentshare similarities with features and principles of operation describedby the other figures, and will therefore not be described in the samedetail in the context of FIG. 18, and vice versa.

FIG. 18 shows a reservoir 611 comprising a thermal material 612. In thisparticular example, the thermal material 612 is a gas, where theindividual molecules or atoms can be magnetically polarized. In otherembodiments, thermal material 612 can be a liquid, or a solid. In otherembodiments, thermal material 612 can comprise other types of magneticdipoles, such as free moving electrons. In other embodiments, themagnetic dipoles can be permanent as opposed to induced by an externallyapplied magnetic field.

An electrically and thermally insulating material 613 encompassesreservoir 611. Reservoir 611 is cylindrical in shape in this embodiment.In other embodiments, reservoir 611 can be rectangular or annular inshape, for example. Reservoir 611 can take any shape in general.

A first heat exchanger 616 is located in the proximity of a first point614 in reservoir 611 and comprises several fins and pipe 617. A secondheat exchanger 621 is located in the proximity of a second point 615 inreservoir 611 and comprises several fins and pipe 622. These heatexchangers are configured in a similar manner as the heat exchangersshown in FIG. 16.

Heat transfer apparatus 610 comprises a body force generating apparatusconfigured to generate a body force per unit mass with a substantialcomponent along the long axis of the page, where the body force per unitmass is acting on the thermal material 612 within reservoir 611.

The body force generating apparatus comprises several current coils,such as coil 629 forming a loop with conductor 630, coil 631 forming aloop with conductor 632, coil 633 forming a loop with conductor 634,coil 635 forming a loop with conductor 636, or coil 637 forming a loopwith conductor 638. Each coil carries a current which is directed out ofthe page on the left side of the page and into the page on the rightside of the page, as indicated. Each coil is made of an electricalconductor, such as copper. In some embodiments, a coil comprisessuperconducting material.

A wide variety of other configurations of a body force per unit massgenerating apparatuses can be devised and employed to produce anpotential energy difference for elements of the thermal material 612between the first point 614 and the second point 615.

The potential energy difference results in a temperature differencebetween the first point 614 and the second point 615 during thermalequilibrium. Due to the increasing magnetic field strength componentalong the direction parallel to the long axis of the page towards thebottom of the page, the magnetic dipoles induced within thermal material612 will experience a body force per unit mass with a non-zero componenttowards the bottom of the page within reservoir 611. As described in thecontext of FIG. 16, this results in a larger temperature at second point615 compared to the first point 614. Thus, embodiment 610 can beoperated as a heat transfer apparatus in the same manner as embodiment520 and other heat transfer apparatuses mentioned herein.

FIG. 19 is a cross-sectional view of one exemplary embodiment 650 of aheat transfer apparatus. Some features of the embodiment shown in FIG.19 as well as some of the principles of operation of the embodimentshare similarities with features and principles of operation describedby the other figures, and will therefore not be described in the samedetail in the context of FIG. 19, and vice versa.

FIG. 19 shows a reservoir 651 comprising a thermal material 652. In thisparticular example, the thermal material 652 is a gas, such as air,helium, or argon. In other embodiments, thermal material 652 can be aliquid.

A thermally insulating material 653 encompasses reservoir 651. Reservoir651 is cylindrical in shape in this embodiment. In other embodiments,reservoir 651 can be rectangular or annular in shape, for example.Reservoir 651 can take any shape in general, provided the forcegenerating apparatus is configured to allow the heat transfer apparatusto be operated as intended.

A first heat exchanger 656 is located in the proximity of a first point654 in reservoir 651 and comprises several fins and pipe 657. A secondheat exchanger 661 is located in the proximity of a second point 655 inreservoir 651 and comprises several fins and pipe 662. The fins of theheat exchangers, such as fin 660 or fin 665 are arranged cylindricallyaround axis 675 in order to provide little resistance to the swirling ofthe thermal material 652 within reservoir 651 during nominal operations.

Heat transfer apparatus 650 comprises a force generating apparatusconfigured to generate a force with a substantial component along thelong axis of the page, directed towards the bottom of the page, wherethe force is acting on the thermal material 652 within reservoir 651.

The force generating apparatus comprises an axial compressor, which isconfigured in a similar manner as an axial compressor of a conventionalturbojet engine. Note that during nominal operations of the depictedembodiment, there is no net flow of the thermal material 652 along thedirection parallel to axis 675. In other embodiments, there can be abulk flow of thermal material 652 along axis 675, provided that asufficient amount of heat is still able to be transferred between thefirst point 654 and the second point 655 during nominal operations. Forexample, when the heat is to be transferred against the direction ofbulk flow of the thermal material 652, the rate of heat transfer isdiminished compared to a thermal material 652 which is stationary onaverage. This is due to the advection of the thermal material partiallycancelling the conduction of heat through the thermal material in theopposite direction. In embodiments in which the thermal material isundergoing bulk flow, the force generating apparatus can also comprisean expanding or contracting cross-sectional area of the channel throughwhich the thermal material is flowing. This can produce a force on thethermal material in a direction upstream or downstream of the bulk flowof the thermal material respectively in an example involving subsonicbulk flow. In other embodiments, therefore, the force generatingapparatus can comprise a contracting or expanding duct. In yet otherembodiments, the force generating apparatus can comprise a centrifugalcompressor. In other embodiments the force generating apparatus cancomprise coaxial, counter-rotating axial compressors.

The axial compressor shown in FIG. 19 comprises a drive shaft 670connected to several rotor discs, each comprising several rotor blades,such as rotor blade 672 or rotor blade 671. In order to balance theswirl of the thermal material 652, several stator discs comprisingseveral blades, such as stator blade 674 or stator blade 673, areconnected to the casing apparatus comprising insulating material 653.The rotor and stator blades are rigidly attached to the shaft 670 or thecasing apparatus in the depicted embodiment. In other embodiments, atleast a portion of the blades is rotably connected to the drive shaft670 or the casing apparatus, where the axis of rotation of said rotableconnection is substantially perpendicular to axis 675. This rotableconnection is configured to allow the angle of attack of the statorand/or rotor blades to be controlled such that the magnitude of theforce applied by the force generating apparatus on the thermal material652 can be regulated.

The axial compressor shown in FIG. 19 is driven by a motor 669. Themotor 669 in FIG. 19 is an electric motor. In other embodiments, themotor 669 can be a piston engine, or a turboshaft engine, for example.In general, any type of power supply and any type of shaft workgenerating apparatus can be employed to drive the axial compressor shownin FIG. 19. Note that the depicted embodiment consumes power duringnominal operations due to frictional losses of the axial compressormoving relative to the thermal material 652. These frictional lossesincrease the temperature of the thermal material 652, which can bedesirable for some applications, such as applications in which the heattransfer apparatus is employed as an artificial heat source. Due tothese frictional losses of the axial compressor, the thermal material652 will swirl, i.e. undergo bulk rotational flow about axis 675 withinreservoir 651. During steady, nominal operations, the rate of rotationof the thermal material 652 is the rate for which the torque applied bythe rotating portion of the axial compressor is balanced by the torqueapplied by the stator, the walls, and other wetter surfaces of thereservoir 651 on the thermal material 652.

During nominal operations, the axial compressor increases thetemperature at the second point 655 compared to the first point 654.Thus, embodiment 610 can be operated as a heat transfer apparatus in thesame manner as embodiment 520 and other heat transfer apparatusesmentioned herein.

In the idealized scenario in which insulating material 653 is perfectlyinsulating, the compression of the thermal material at second point 655compared to first point 654 can be modelled as an adiabatic compression.In other embodiments, the compression is not adiabatic.

FIG. 20 is a cross-sectional view of one exemplary embodiment 690 of anartificial heat source or artificial heat sink employing a heat transferapparatus. Some features of the embodiment shown in FIG. 20 as well assome of the principles of operation of the embodiment share similaritieswith features and principles of operation described by the otherfigures, and will therefore not be described in the same detail in thecontext of FIG. 20, and vice versa.

FIG. 20 shows a heat transfer apparatus comprising a reservoir 691 whichin turn comprises a thermal material 692. In this particular example,the thermal material 692 is a gas, In other embodiments, thermalmaterial 692 can be a liquid, or a solid

A thermally insulating material 693 encompasses reservoir 691. Reservoir691 is cylindrical in shape in this embodiment. In other embodiments,reservoir 691 can be rectangular or annular in shape, for example.Reservoir 691 can take any shape in general.

A first heat exchanger 698 is located in the proximity of a first point695 in reservoir 691 and comprises several fins, such as fin 702, andpipe 699. A second heat exchanger 703 is located in the proximity of asecond point 696 in reservoir 691 and comprises several fins, such asfin 707, and pipe 704. These heat exchangers are configured in a similarmanner as the heat exchangers shown in FIG. 16. The pumps which pump thethermal fluid through pipe 699 and pipe 704 are not shown forsimplicity.

The heat transfer apparatus can be of any suitable configuration, suchas a configuration shown in FIG. 16, FIG. 17, FIG. 18, or FIG. 19, orany other configuration discussed herein or within the scope of theinvention. Detailed features of the heat transfer apparatus, such asfeatures pertaining to the force generating apparatus, are not shown forsimplicity and generality.

In FIG. 20, a first exterior reservoir, located on the portion of firstheat exchanger 698 which is located outside of reservoir 691, is shown.For example, the first exterior reservoir can be the earth's atmosphere.The temperature of the atmosphere at point 694 and the temperature atpoint 697 as well as the equilibrium temperature difference betweenfirst point 695 and second point 696 of the heat transfer apparatus,determine the rate of heat transfer, as well as the direction of heattransfer through the heat transfer apparatus, as discussed in thecontext of FIG. 16.

A second exterior reservoir 710 comprising thermal material 711, locatedon the portion of second heat exchanger 703 which is located outside ofreservoir 691, is shown. The second exterior reservoir can be theinterior of a building, a vehicle, or a refrigerator, for example,Depending on the material properties of the thermal material 692, thedirection of the force applied to the thermal material 692, as well asthe temperature of the larger exterior reservoir, i.e. the temperatureat point 694 in the first exterior reservoir in this case, heat can bemade to flow from the first exterior reservoir to the second exteriorreservoir, or vice versa. From the perspective of the second exteriorreservoir, the heat transfer apparatus can thus be configured to be anartificial heat source or an artificial heat sink.

Notes and Examples

The following, non-limiting examples, detail certain aspects of thepresent subject matter to solve the challenges and provide the benefitsdiscussed herein, among others.

In one aspect, a heat exchange system comprises a first reservoir havinga first point and a second point; a first thermal material contained inthe first reservoir; a first thermal contact thermally coupled with thefirst point; and a second thermal contact thermally coupled with thesecond point, and wherein application of a force to the first thermalmaterial can result in a temperature difference between the first andsecond points.

The system may further comprise a second reservoir having a first pointand a second point; and a second thermal material contained in thesecond reservoir, wherein at least some thermodynamic properties of thesecond material are different than the first material.

A distance between the first point and the second point of the firstreservoir or the second reservoir may be less than 100 kilometers.

The first thermal material may comprise a gas, a liquid, or a solidmaterial.

The force may comprise a body force or a mechanical force.

A method for facilitating heat flow may comprise employing a firstreservoir having a first point and a second point; employing a firstthermal material contained in the first reservoir; where the firstthermal material is subjected to a force thereby forming a temperaturedifference between the first and second points; allowing heat flowthrough the first thermal material between a first thermal contactadjacent the first point and a second thermal contact adjacent thesecond point.

The method may further comprise employing a second reservoir having afirst point and a second point; employing a second thermal materialcontained in the second reservoir, wherein at least some thermodynamicproperties of the second material are different than the first material;and wherein the second thermal material is subjected to a force therebyforming a temperature difference between the first and second points inthe second reservoir.

Applying the force may comprise applying a body force or a mechanicalforce to the first material.

The first material may comprise a gas, a liquid, or a solid material.

A method for facilitating heat flow may comprise employing a firstreservoir containing a first thermal material, the first thermalmaterial having a first point and a second point; employing a secondreservoir containing a second thermal material, the second reservoirhaving a first point and a second point, wherein at least somethermodynamic properties of the second material are different than thefirst material; wherein the first thermal material in the firstreservoir is subjected to a force, and wherein the second thermalmaterial in the second reservoir is subjected to a force, therebycreating a temperature difference between the first point and the secondpoint in the first reservoir, and creating a temperature differencebetween the first point and the second point in the second reservoir;allowing heat to flow between the first and second points in the firstreservoir and between the first and second points in the secondreservoir; and allowing heat to flow between the second point in thefirst reservoir and the second point in the second reservoir.

The method may further comprise flowing heat between a third reservoircontaining a third thermal material and the first point in the firstthermal material in the first reservoir.

The third material may be different than the first material.

The method may further comprise flowing heat between the first point inthe second reservoir and a fourth reservoir containing a fourth thermalmaterial.

The fourth thermal material may be the same or different than the secondthermal material.

The method may further comprise at least partially thermally insulatingthe first reservoir or the second reservoir from each other.

Flowing heat between the second points in the first and secondreservoirs or between the first and second points in either the firstreservoir or second reservoir may comprise conduction, radiation,natural convection, or forced convection.

Flowing heat between the second points in the first and secondreservoirs or between the first and second points in either the firstreservoir or second reservoir may comprise pumping a fluid through aheat exchanger or creating a vacuum therein.

Flowing heat between the second points in the first and secondreservoirs or between the first and second points in either the firstreservoir or second reservoir may comprise transmitting electromagneticwaves.

The method may further comprise accelerating the first reservoir or thesecond reservoir.

The method may further comprise regulating a rate of heat flow throughthe first reservoir or the second reservoir.

Providing the force may comprise applying a constant body force inmagnitude and direction over time within the first and the secondreservoirs during nominal operation.

The first or the second thermal material may comprise electrical chargedelements and wherein providing the force comprises producing anelectrical potential difference between the first and second points ineither of the first and second reservoirs.

The first or the second material may comprise electric dipoles, andwherein providing the force may comprise producing an electrical fieldgradient between the first or second points in either of the first andsecond reservoirs.

Providing the force may comprise subjecting the first and second pointsin either of the first and second reservoirs to a gravitationalpotential difference or accelerating the first or second reservoirs ininertial space.

The first or the second thermal material may comprise magnetic dipolesand wherein providing the force may comprise subjecting the first or thesecond materials to a magnetic field.

Applying the force may comprise a thermodynamic compressor or expander.

The thermodynamic compressor or expander may comprise an axialcompressor or turbine, a centrifugal compressor or turbine, or aconverging or diverging duct.

A heat exchange system may comprise a first reservoir having a firstpoint and a second point; a first thermal material contained in thefirst reservoir; a second reservoir having a first point and a secondpoint; a second thermal material contained in the second reservoir,wherein at least some thermodynamic properties of the second materialare different than the first material; and a thermal contact between thesecond point of the first reservoir and the second point of the secondreservoir so that heat can transfer from the second point in the firstreservoir to the second point in the second reservoir via the thermalcontact where the first reservoir is subject to a force acting toproduce a temperature difference between the first point and the secondpoint of the first reservoir, and wherein the second reservoir can besubject to a force acting to produce a temperature difference betweenthe first point and the second point of the second reservoir

The system may further comprise a third reservoir containing a thirdthermal material and a second heat exchanger operably coupled to thefirst and third reservoirs such that heat can be exchanged from thethird reservoir to the first point of the first reservoir.

The third thermal material may be the same or different than the firstthermal material.

The system may further comprise a fourth reservoir containing a fourththermal material and a thermal contract operably coupled to the secondand fourth reservoirs such that heat can be exchanged from the firstpoint of the second reservoir to the fourth reservoir.

The fourth thermal material may be the same or different than the secondthermal material.

The system may further comprise thermal insulation along the path of theheat flow between the first point and the corresponding second point ineither the first or second thermal material.

The thermal contact may be achieved via conduction, radiation, naturalconvection, or forced convection.

The first material or the second material may be configured tofacilitate the transfer of heat between the first and second points ineither the first reservoir or second reservoir, and wherein the transferof heat is by conduction, radiation, natural convection, or forcedconvection.

The system may further comprise a motor for accelerating the firstreservoir or the second reservoir.

The system may further comprise a heat flow regulator configured toregulate heat flow through the first reservoir, the second reservoir, orthe heat exchanger.

The system may further comprise a force applying mechanism configured toapply the force to the first and second reservoirs.

The force applying mechanism may comprise turbomachinery or a body forcegenerating apparatus.

A method for facilitating heat flow may comprise employing a firstreservoir containing a first thermal material, the first reservoirhaving a first point and a second point; employing a second reservoir,transferring heat from the first reservoir to the second reservoir whenthe second reservoir is at a lower temperature relative to the firstreservoir, or transferring heat from the second reservoir to the firstreservoir when the second reservoir is at a higher temperature relativeto the first reservoir; employing a force to the first thermal materialthereby creating a temperature difference between the first point andthe second point in the first reservoir; operably coupling or operablydecoupling a second heat exchange apparatus disposed in the firstreservoir with a first heat exchange apparatus disposed in the secondreservoir thereby allowing heat to flow therebetween or preventing heatto flow therebetween; operably coupling or operably decoupling a thirdheat exchange apparatus disposed in the first reservoir with a fourthheat exchange apparatus disposed in the second reservoir therebyallowing heat to flow therebetween or preventing heat to flowtherebetween; actuating a work exchange apparatus to perform work on thefirst material; and actuating the work exchange apparatus to allow thefirst material to perform work on the work exchange apparatus.

The second reservoir may have a first point and a second point andwherein the second reservoir contains a second thermal material, thesecond thermal material having at least some thermodynamic propertiesdifferent than the first thermodynamic material.

The second heat exchange apparatus may be disposed adjacent the firstpoint of the first reservoir, and wherein the third heat exchangeapparatus is disposed adjacent the second point of the first reservoir.

The first reservoir may be a closed reservoir or an open reservoir.

The method may further comprise providing an insulating material betweenthe first and second reservoirs.

Actuating the work exchange apparatus may comprise actuating a piston, aturbine, or a nozzle.

The method may further comprise changing a pressure in the secondreservoir.

The method may further comprise controlling heat flow between the secondor third heat exchange apparatus with the respective first or fourthheat exchange apparatus.

Providing the force may comprise actuating the work exchange apparatus.

Employing the force may comprise providing an inertial force, agravitational force, or an electromagnetic force.

A heat exchange system may comprise a first reservoir containing a firstthermal material having a first point and a second point; a secondreservoir wherein heat is transferred from the first reservoir to thesecond reservoir when the second reservoir is at a lower temperaturerelative to the first reservoir, or wherein heat is transferred from thesecond reservoir to the first reservoir when the second reservoir is ata higher temperature relative to the first reservoir; a second heatexchange apparatus in the first reservoir operably couplable anddecouplable with a first heat exchange apparatus in the second reservoirto allow heat to flow therebetween or to prevent heat flow therebetween;a third heat exchange apparatus in the first reservoir operablycouplable and decouplable with a fourth heat exchange apparatus in thesecond reservoir to allow heat to flow therebetween or to prevent heatflow therebetween, wherein application of a force to the first thermalmaterial forms a temperature difference between the first point and thesecond point in the first reservoir; and an actuatable work exchangeapparatus, wherein actuation of the work exchange apparatus performswork on the first material, and wherein actuation of the work exchangeapparatus allows the first material to perform work on the work exchangeapparatus.

The second reservoir may contain a second thermal material having afirst point and a second point, and wherein the at least somethermodynamic properties of the second material are different than thefirst material.

The first reservoir may be a closed reservoir or an open reservoir.

The system may further comprise an insulating material between the firstand outside reservoirs.

The system may further comprise a force generating apparatus configuredto provide the force to the first material.

The force generating apparatus may comprise an inertial force mechanismor an electromagnetic force mechanism.

The work exchange apparatus may comprise a piston, a turbine, or anozzle.

The system may further comprise a heat flow control operably coupled tothe first or the third heat exchange apparatus and a respective first orfourth heat exchange apparatus, the heat flow control configured tocontrol heat flow therebetween.

An energy conversion system may comprise a first reservoir containing afirst material; a first expander having an inflow end and an outflowend, wherein the first material is input into the inflow end and outputfrom the outflow end; a heat transfer apparatus having a first pointthermally coupled to the outflow of the first material from the firstexpander and configured to extract heat from or deliver heat to thefirst material in the output of the first expander; and a compressorconfigured to receive outflow of the first working material from theheat transfer apparatus, wherein the outflow from the compressor isreleased into the first reservoir.

The heat may be transferred between the first reservoir and the firstmaterial output from the first expander.

The first expander may comprise a piston, a centrifugal or axialturbine, a duct, or a nozzle.

The compressor may comprise a piston, a centrifugal or axial compressor,a duct or a nozzle.

Heat extracted from the first material output from the outflow end ofthe expander may be delivered to the first reservoir or heat isextracted from the first reservoir and exchanged with the first materialoutput from the outflow end of the expander.

The system may further comprise a second compressor having an inflow endand an outflow end, wherein a second material is input into the secondcompressor inflow end and output from the outflow end; the heat transferapparatus may have a second point thermally coupled with the outflow ofthe material from the second compressor and configured to deliver heatto or extract heat from the material in the outflow of the secondcompressor, wherein the outflow of the second material from the heattransfer apparatus is input into an input of the second expander and anoutflow from the second expander is released into the first reservoir.

Heat may be transferred between the first reservoir and outflow of thefirst material from the first compressor.

The second material may be the same as or different than the firstmaterial.

An energy conversion system may comprise a first material contained in afirst reservoir; a first compressor having an inflow end and an outflowend, wherein the first material is input into the first compressorinflow end and output from the outflow end; a heat transfer apparatushaving a first point thermally coupled with the outflow of the firstmaterial from the first compressor and configured to deliver heat to orextract heat from the first material in the output of the firstcompressor; and a first expander, wherein outflow of the first materialfrom the heat transfer apparatus is input into an input of the firstexpander and an outflow from the first expander is released into thefirst reservoir.

The heat extracted from the first material output from the outflow endof the compressor may be exchanged with the first reservoir or heat isextracted from the first reservoir and exchanged with the first materialoutput from the outflow end of the first compressor.

A method of converting energy may comprise providing a first materialcontained in a first reservoir; inputting the first material into aninflow end of a first expander and outputting the first material from anoutflow end of the first expander; transferring heat between the firstmaterial output from the first expander and a heat transfer apparatus;inputting the first material output from the heat transfer apparatusinto a first compressor; and releasing an outflow from the firstcompressor into the first reservoir.

The method may further comprise providing a second material contained inthe first reservoir; inputting the second working material into aninflow end of a second compressor; transferring heat between the heattransfer apparatus and the second working material output from anoutflow of the second compressor; and inputting outflow from the heattransfer apparatus into a second expander and outputting outflow from anoutput of the second expander into the first reservoir.

The second material maybe the same as or different than the firstmaterial.

An energy conversion system may comprise a first reservoir containing afirst material; a first compressor having an inflow end and an outflowend, wherein the first material is input into the inflow end; anexpander; a heat transfer apparatus, wherein outflow from the firstcompressor can exchange heat with a first point of a heat transferapparatus, and wherein outflow from the expander can exchange heat witha second point of the heat transfer apparatus, wherein the outflow fromthe first compressor after exchanging heat with the heat transferapparatus is input into the expander; and a second compressor, whereinoutflow from the expander flows into the second compressor afterexchanging heat with the heat exchanger, and wherein outflow from thesecond compressor is released into the first reservoir.

The system may further comprise a heat exchanger thermally coupled withthe heat transfer apparatus and configured to exchange heat therewith.

A method of converting energy may comprise providing a first materialdisposed in a first reservoir inputting the first material into a firstcompressor; outputting the first material from the first compressor andexchanging heat with a first point in a heat transfer apparatus;inputting the first material into an expander after exchanging heat withthe heat transfer apparatus; outputting the first material from theexpander and exchanging heat with a second point in the heat transferapparatus; inputting the first material into a second compressor afterexchanging heat with the heat transfer apparatus; powering the secondcompressor; and releasing outflow from the second compressor.

The method may further comprise exchanging heat between the heattransfer apparatus and a heat exchanger.

An energy conversion system may comprise a first reservoir containing afirst working material; a first expander having an inflow end and anoutflow end, wherein the first working material is input into the inflowend; a first point of a heat transfer apparatus configured to exchangeheat with outflow of the first working material from the outflow end ofthe first expander; a compressor, wherein the outflow of the firstmaterial from the first expander is input into the compressor afterexchanging heat with the heat transfer apparatus; and a second point ofa heat transfer apparatus for exchanging heat with the first workingmaterial output from the compressor, wherein outflow of the firstworking material from the compressor is input into the second expanderafter exchanging heat with the heat transfer apparatus, and whereinoutflow from the second expander is released into the first reservoir.

The system may further comprise a heat exchanger thermally coupled withthe heat transfer apparatus and configured to exchange heat therewith.

A method of converting energy may comprise providing a first workingmaterial in a first reservoir; inputting the first working material intoa first expander; exchanging heat between a first point of a heattransfer apparatus and output from the first expander; inputting thefirst working material into a compressor after exchanging heat with theheat exchanger; powering the compressor; exchanging heat between asecond point of the heat transfer apparatus and outflow from thecompressor; inputting the first working material into the secondexpander after exchanging heat with the heat transfer apparatus; andreleasing outflow from the second expander into the first reservoir.

The method may further comprise exchanging heat between the heattransfer apparatus and a heat exchanger.

An engine may comprise a duct apparatus having an inlet and an outletwith a channel extending therethrough; a first working material disposedin the channel; a first compressor, wherein the first working materialpasses therethrough; a first heat exchanger, wherein the first workingmaterial passes therethrough and heat is exchanged between the firstworking material and the first heat exchanger; a first expander, whereinthe first working material passes therethrough after exiting the firstcompressor; a first chamber disposed within or downstream of the firstcompressor or within or upstream of the first expander, wherein thefirst heat exchanger is disposed in the first chamber; a second heatexchanger, wherein the first working material passes therethrough andheat is exchanged between the first working material and the second heatexchanger; a second compressor, wherein the first working materialpasses therethrough, and wherein the first working material exits thesecond compressor and exits the outlet of the duct apparatus; a secondchamber disposed within or downstream of the first expander or within orupstream of the second compressor, wherein the second heat exchanger isdisposed in the second chamber; and a heat transfer apparatus configuredto transfer heat between the first heat exchanger and the second heatexchanger, wherein the heat transfer can be from the second chamber tothe first chamber when net work is done by the first working material,or where a rate of the heat transfer can be from the first chamber intothe second chamber when net work is done on the working material.

A method of converting energy may comprise providing a channel in a ductapparatus; inputting a first material into the channel and into a firstcompressor and compressing the first material; passing the firstmaterial within or after the first compressor through a first heatexchanger; passing the first material output from the first compressorthrough a first expander after or while being heated and expanding thefirst working material; cooling the first working material after orwhile expanding it in the first expander with a second heat exchanger;and compressing the first working material after or while cooling thefirst working material in the second heat exchanger.

An engine may comprise a first engine comprising a duct apparatus with achannel disposed therethrough; a first working material disposed in thechannel; a first expander, wherein the first working material enters thefirst expander; a first heat exchanger configured to exchange heat withthe first material; a first compressor, wherein the first heat exchangeris disposed within or downstream of the first expander or within orupstream of the first compressor, and wherein the first material entersthe first compressor after exiting the first expander, and wherein thefirst material exits the first compressor.

The engine may further comprise a second engine comprising a ductapparatus with a channel disposed therein; a second working materialdisposed in the channel; a second compressor, wherein the second workingmaterial is input into the second compressor; a second heat exchangerconfigured to transfer heat with the second working material; and asecond expander, wherein the second heat exchanger is disposed withinthe second compressor or downstream of the second compressor or upstreamof the second expander or within the second expander, and wherein thesecond working material is input into the second expander after exitingthe second compressor.

The first material may be the same as or different than the secondmaterial.

A method of converting energy may comprise providing a first enginecomprising a duct apparatus with a channel disposed therethrough;passing a first working material along the channel; inputting the firstworking material into a first expander; passing the first workingmaterial through a first heat exchanger and exchanging heattherebetween; compressing the first working material in a firstcompressor wherein the first heat exchanger is disposed in a firstchamber disposed within or downstream of the first expander and withinor upstream of the first compressor.

The method may further comprise providing a second engine comprising aninside apparatus disposed in a duct apparatus with a channel disposedtherebetween; disposing a second working material in the channel;inputting the second working material into a second compressor; passingthe second working material through a second heat exchanger andexchanging heat therebetween; inputting the second working into a secondexpander, and wherein the second heat exchanger is disposed in a secondchamber disposed within or downstream of the second compressor or withinor upstream of the second expander.

The second working material may be the same as or different than thefirst working material.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

1. A heat transfer system, said system comprising a first reservoirhaving a first point and a second point; a first thermal materialcontained in the first reservoir; a first thermal contact thermallycoupled with the first point; and a second thermal contact thermallycoupled with the second point, and wherein application of a force to thefirst thermal material can result in a temperature difference betweenthe first and second points, and wherein heat can flow between the firstand second points in the first reservoir.
 2. The system of claim 1,further comprising a second reservoir having a first point and a secondpoint; and a second thermal material contained in the second reservoir,wherein at least one thermodynamic property of the second material isdifferent than the first material, and wherein subjecting the secondthermal material to a force causes a temperature difference between thefirst and second points in the second reservoir, and wherein the secondpoint in the second reservoir is in thermal contact with the secondpoint in the first reservoir.
 3. (canceled)
 4. The system of claim 1,wherein a distance between the first point and the second point is lessthan 100 kilometers.
 5. The system of claim 1, wherein the first thermalmaterial comprises a gas, a liquid, or a solid material.
 6. The systemof claim 1, wherein the force comprises a body force or a mechanicalforce.
 7. A method for facilitating heat flow, said method comprisingemploying a first reservoir having a first point and a second point;employing a first thermal material contained in the first reservoir,wherein the first thermal material is subjected to a force therebyforming a temperature difference between the first and second points;and allowing heat flow through the first thermal material between thefirst point and the second point.
 8. The method of claim 7, furthercomprising employing a second reservoir having a first point and asecond point; employing a second thermal material contained in thesecond reservoir, wherein at least one thermodynamic property of thesecond material is different than the first material; and wherein thesecond thermal material is subjected to a force thereby forming atemperature difference between the first and second points in the secondreservoir, and providing a thermal contact between the second point inthe second reservoir and the second point in the first reservoir.
 9. Themethod of claim 7, wherein the force comprises a body force or amechanical force in the first material.
 10. The method of claim 7,wherein the first material comprises a gas, a liquid, or a solidmaterial.
 11. (canceled)
 12. The method of claim 7, further comprisingflowing heat between a second reservoir containing a second thermalmaterial and the first point in the first thermal material in the firstreservoir.
 13. The method of claim 12, wherein the second material isdifferent than the first material.
 14. The method of claim 8, furthercomprising flowing heat between the first point in the second reservoirand a third reservoir containing a third thermal material.
 15. Themethod of claim 14, wherein the third thermal material is different thanthe second thermal material. 16.-29. (canceled)
 30. The system of claim1, further comprising a second reservoir containing a second thermalmaterial and a second heat exchanger operably coupled to the first andsecond reservoirs such that heat can be exchanged between the secondreservoir and the first point of the first reservoir.
 31. The system ofclaim 30, wherein the second thermal material is different than thefirst thermal material.
 32. The system of claim 2, further comprising athird reservoir containing a third thermal material and a thermalcontact operably coupled to the second and id reservoirs such that heatcan be exchanged between the first point of the second reservoir to adthe third reservoir.
 33. The system of claim 32, wherein the thirdthermal material is different than the second thermal material. 34.(canceled)
 35. The system of claim 1, wherein the thermal contact isachieved via conduction, radiation, natural convection, or forcedconvection.
 36. The system of claim 1, wherein the first material isconfigured to facilitate the transfer of heat between the first andsecond points in the first reservoir, and wherein the transfer of heatis by conduction, radiation, natural convection, or forced convection.37.-87. (canceled)
 88. The system of claim 1, further comprising atleast partial thermal insulation disposed along a path of the heat flowbetween the first point and the second point in the first thermalmaterial.
 89. The system of claim 1, further comprising a heat flowregulator configured to regulate heat flow through the first reservoir,or the heat transfer system.
 90. The system of claim 1, furthercomprising an accelerator configured to accelerate the first reservoir.91. The system of claim 90, further comprising a motor for acceleratingthe first reservoir.
 92. The system of claim 6, further comprising abody force generating apparatus configured to apply the body force, andwherein the body force is constant in magnitude and direction within thefirst reservoir during normal operation.
 93. The system of claim 1,wherein the first thermal material comprises electrical charged elementsand wherein at least a portion of the force is provided by an electricalpotential difference between the first and second points in the firstreservoir.
 94. The system of claim 1, wherein the first materialcomprises electric dipoles, and wherein at least a portion of the forceis provided by an electrical field gradient between the first and secondpoint the first reservoir.
 95. The system of claim 1, wherein at least aportion of the force is provided by a gravitational potential differenceapplied to the first and second points in the first reservoir, or byacceleration of the first and second points the first reservoir ininertial space.
 96. The system of claim 1, wherein the first thermalmaterial comprises magnetic dipoles and wherein at least a portion ofthe force is provided by a non-uniform magnetic field.
 97. The system ofclaim 1, wherein any materials thermally connected by the first or thesecond thermal contact are different materials.
 98. The system of claim2, wherein heat flows between the second points in the first and secondreservoirs, or heat flows between the first and second points in eitherthe first reservoir or the second reservoir, and the heat flow comprisesconduction, radiation, natural convection, or forced convection.
 99. Thesystem of claim 2, wherein the second thermal material comprises a gas,a liquid, or a solid material.
 100. The system of claim 2, wherein thethermodynamic property comprises the specific heat capacity at constantpressure.
 101. The system of claim 6, wherein at least a portion of themechanical force is provided by a thermodynamic compressor or expander.102. The system of claim 101, wherein the thermodynamic compressor orexpander comprises an axial compressor or turbine, a centrifugalcompressor or turbine, or a converging or diverging duct.
 103. Themethod of claim 7, further comprising at least partially thermallyinsulating the first reservoir along a path of the heat flow between thefirst point and the second point in the first thermal material.
 104. Themethod of claim 7, further comprising accelerating the first reservoir.105. The method of claim 7, further comprising regulating a rate of heatflow through the first reservoir.
 106. The method of claim 9, whereinthe force comprises a body force constant in magnitude and directionwithin at least a portion of the first reservoir during nominaloperation.
 107. The method of claim 7, wherein the first thermalmaterial comprises electrical charged elements and wherein at least aportion of the force is provided by an electrical potential differencebetween the first and second points in the first reservoir.
 108. Themethod of claim 7, wherein the first material comprises electricdipoles, and wherein the at least a portion of the force is provided byproducing an electrical field gradient between the first and secondpoint the first reservoir.
 109. The method of claim 7, wherein at leasta portion of the force is provided by subjecting the first and secondpoints in the first reservoir to a gravitational potential difference oraccelerating the first reservoir in inertial space.
 110. The method ofclaim 7, wherein the first thermal material comprises magnetic dipolesand wherein at least a portion of the force is provided by subjectingthe first material to a non-uniform magnetic field.
 111. The method ofclaim 7, wherein allowing the heat flow through the first thermalmaterial between the first and second points in the first reservoir,comprises transferring the heat by conduction, radiation, naturalconvection, or forced convection.
 112. The method of claim 8, furthercomprising flowing heat between the second points in the first andsecond reservoirs or flowing heat between the first and second points ineither the first reservoir or second reservoir, and wherein the heatflow comprises conduction, radiation, natural convection, or forcedconvection.
 113. The system of claim 8, wherein the thermodynamicproperty comprises the specific heat capacity at constant pressure. 114.The system of claim 8, wherein the second material comprises a gas, aliquid, or a solid material.
 115. The method of claim 9, whereinapplying the mechanical force comprises a thermodynamic compressor orexpander.
 116. The method of claim 115, wherein the thermodynamiccompressor or expander comprises an axial compressor or turbine, acentrifugal compressor or turbine, or a converging or diverging duct.117. The method of claim 9, further comprising employing a body forcegenerating apparatus to produce the body force.